patch expiry warning: handle System UI force stops

The JobScheduler service will cancel jobs from apps that have been force stopped. In SystemUI's
case, the app seems to still run when the main user force stops the app, but the intent that is
broadcast on app force stopped is still fired off. JobSchedulerService log output beforehand:

Got android.intent.action.PACKAGE_RESTARTED for 10125/com.android.systemui
Pulled stopped state of com.android.systemui (10125): false
Removing jobs for pkg com.android.systemui at uid 10125
CANCEL: b9480f5 #u0a125/450000 com.android.systemui/.patchlevelwarning.PeriodicPatchLevelExpiryCheck
Got android.intent.action.PACKAGE_UNSTOPPED for 10125/com.android.systemui

Author: inthewaves

packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java

@@ -1448,6 +1448,12 @@ public void onPrimaryBouncerShowingChanged() {
 
     private final Lazy<PatchLevelWarningDialogDelegate> mPatchLevelWarningDialogDelegate;
 
+    private boolean mIsPatchLevelWarningEnabled = true;
+
+    private long mPatchLevelJobScheduleKeyguardCheckLastTimeRun = 0;
+
+    private final long PATCH_LEVEL_JOB_SCHEDULE_KG_CHECK_INTERVAL = 24 * 60 * 60 * 1000; // 1 day
+
     private final Handler mBgHandler;
 
     private final GlobalSettings mGlobalSettings;
@@ -1694,7 +1700,8 @@ private void setupLocked() {
         final ContentObserver observer = new ContentObserver(mBgHandler) {
             @Override
             public void onChange(boolean selfChange) {
-                if (PeriodicPatchLevelExpiryCheck.isPatchLevelWarningEnabled(mContext)) {
+                mIsPatchLevelWarningEnabled = PeriodicPatchLevelExpiryCheck.isPatchLevelWarningEnabled(mContext);
+                if (mIsPatchLevelWarningEnabled) {
                     PeriodicPatchLevelExpiryCheck.schedule(mContext, false);
                 } else {
                     mPatchLevelWarningDialogDelegate.get().markDontShowOnKeyguard();
@@ -2855,9 +2862,28 @@ private void sendUserPresentBroadcast() {
                     }
                     mLockPatternUtils.userPresent(currentUserId);
 
+                    // Ensure expiry warning job is always scheduled if warning enabled.
+                    // Job might be cancelled if the main user of device force stops SystemUI
+                    // (force stopping System UI will still cause System UI to function)
+                    if (mIsPatchLevelWarningEnabled) {
+                        // limit number of calls to JobScheduler.getPendingJob
+                        final long now = System.currentTimeMillis();
+                        final long timeBetween = now - mPatchLevelJobScheduleKeyguardCheckLastTimeRun;
+                        if (timeBetween > PATCH_LEVEL_JOB_SCHEDULE_KG_CHECK_INTERVAL) {
+                            mPatchLevelJobScheduleKeyguardCheckLastTimeRun = now;
+                            if (!PeriodicPatchLevelExpiryCheck.isJobScheduled(mContext)) {
+                                Log.w(TAG, "expected PeriodicPatchLevelExpiryCheck to be scheduled; rescheduling");
+                                PeriodicPatchLevelExpiryCheck.schedule(mContext, false);
+                            }
+                        }
+                    }
+
                     // Show expiry warning popup
                     // This *could* be done as a separate app, but an implicit broadcast receiver
                     // in a manifest wouldn't receive this broadcast.
+                    //
+                    // The periodic service marks the local variables in the delegate to avoid
+                    // having to do calculations on every keyguard unlock.
                     if (mPatchLevelWarningDialogDelegate.get().shouldShowOnThisKeyguardUnlock()) {
                         maybeShowPatchLevelExpiredDialog();
                     }
@@ -2876,8 +2902,9 @@ private void maybeShowPatchLevelExpiredDialog() {
         mPatchLevelWarningDialogDelegate.get().beforeDialogShown();
         // Although the periodic service will mark us to show the dialog on keyguard unlock,
         // need to sanity check this against the actual expiry state and setting
+        mIsPatchLevelWarningEnabled = PeriodicPatchLevelExpiryCheck.isPatchLevelWarningEnabled(mContext);
         if (PeriodicPatchLevelExpiryCheck.isPatchLevelExpiredOrUnparseable() &&
-                PeriodicPatchLevelExpiryCheck.isPatchLevelWarningEnabled(mContext)) {
+                mIsPatchLevelWarningEnabled) {
             // post to UI thread of keyguard because possibly still holding a lock here, and
             // should finish rest of keyguard animations
             mHandler.post(() -> mPatchLevelWarningDialogDelegate.get().createDialog().show());

packages/SystemUI/src/com/android/systemui/patchlevelwarning/PeriodicPatchLevelExpiryCheck.kt

@@ -146,6 +146,13 @@ class PeriodicPatchLevelExpiryCheck : JobService() {
             return LocalDate.now() >= getWarningStartDate(securityPatchLocalDate)
         }
 
+        @JvmStatic
+        fun isJobScheduled(context: Context): Boolean {
+            val jobScheduler = context.getSystemService(JobScheduler::class.java)
+            return (jobScheduler.getPendingJob(JOB_ID) != null)
+                .also { scheduled -> Log.d(TAG, "isJobScheduled = $scheduled") }
+        }
+
         @JvmStatic
         fun schedule(context: Context, isFromBoot: Boolean = false) {
             // SystemUI should only be from system user