Don't remove ourselves from the installed app cache.

If F-Droid was actually removed, then we wouldn't even
have an installed app cache (we aren't even on the device
any more). As such, ignore all requests to remove F-Droid
because it complicates the installed apk cache. Specifically,
there is a race condition between the "compare apk cache to
package manager" and the "package removed receiver", where
the later was overriding the former.

app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java

@@ -164,6 +164,7 @@ public class InstalledAppProviderService extends IntentService {
      * @see <a href="https://gitlab.com/fdroid/fdroidclient/issues/819>issue #819</a>
      */
     public static void compareToPackageManager(Context context) {
+        Utils.debugLog(TAG, "Comparing package manager to our installed app cache.");
         Map<String, Long> cachedInfo = InstalledAppProvider.Helper.all(context);
 
         List<PackageInfo> packageInfoList = context.getPackageManager()

app/src/main/java/org/fdroid/fdroid/receiver/PackageManagerReceiver.java

@@ -3,6 +3,7 @@ package org.fdroid.fdroid.receiver;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.text.TextUtils;
 
 import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.data.InstalledAppProviderService;
@@ -26,7 +27,11 @@ public class PackageManagerReceiver extends BroadcastReceiver {
             if (Intent.ACTION_PACKAGE_ADDED.equals(action)) {
                 InstalledAppProviderService.insert(context, intent.getData());
             } else if (Intent.ACTION_PACKAGE_REMOVED.equals(action)) {
-                InstalledAppProviderService.delete(context, intent.getData());
+                if (TextUtils.equals(context.getPackageName(), intent.getData().getSchemeSpecificPart())) {
+                    Utils.debugLog(TAG, "Ignoring request to remove ourselves from cache.");
+                } else {
+                    InstalledAppProviderService.delete(context, intent.getData());
+                }
             } else {
                 Utils.debugLog(TAG, "unsupported action: " + action + " " + intent);
             }