Fix appMetadataFilePath when restoring system app

When restoring a disabled system app the appMetadataFilePath field was
not being copied over from the disabled PackageSetting to the new
PackageSetting. This is now copied over in enableSystemPackageLPw.

The appMetadataFilePath was also being set in commitPackageSettings
which is shared code path for both installs and restores. This was
causing the appMetadataFilePath to be set to null when restoring. Moved
the relevant code instead to commitPackagesLocked so that it only sets
for installs and not restores.

Also added GET_APP_METADATA permission check to guard the
get-app-metadata adb command.

Bug: 281589646
Test: Manual
Test: atest android.packageinstaller.install.cts.InstallAppMetadataTest
Change-Id: I69b90d61b1f53f8eaefc2adf719eca99f77e81ea