Collect APK certificates after an OTA, rather than relying on timestamps

Checking APK file modified timestamps is not a reliable signal to
determine that the APK signature may have changed. APKs in the system
image (anything that passes through add_img_to_target_files) have all
file timestamps rewritten to 2009-01-01, for instance, so timestamp will
explicitly fail to detect changes in the platform key across an OTA.

Bug: 80093599
Bug: 74501739
Test: Verified OTA between test-keys and dev-keys worked for 2 builds
with same APK timestamps, and signature changes were picked up.
Change-Id: Id3e5afbfe22e63d70cd176f1e438e2fa143ccd65

services/core/java/com/android/server/pm/PackageManagerService.java

@@ -8912,10 +8912,10 @@ public class PackageManagerService extends IPackageManager.Stub
                     + " better than this " + pkg.getLongVersionCode());
         }
 
-        // Verify certificates against what was last scanned. If it is an updated priv app, we will
-        // force re-collecting certificate.
-        final boolean forceCollect = PackageManagerServiceUtils.isApkVerificationForced(
-                disabledPkgSetting);
+        // Verify certificates against what was last scanned. If there was an upgrade or this is an
+        // updated priv app, we will force re-collecting certificate.
+        final boolean forceCollect = mIsUpgrade ||
+                PackageManagerServiceUtils.isApkVerificationForced(disabledPkgSetting);
         // Full APK verification can be skipped during certificate collection, only if the file is
         // in verified partition, or can be verified on access (when apk verity is enabled). In both
         // cases, only data in Signing Block is verified instead of the whole file.