Remove app metadata if data is null or empty

The getAppMetadata API will now remove any metadata that may have
already been set in the same install session if the data param is set to
null or a empty bundle.

Bug: 265896861
Test: atest android.packageinstaller.install.cts.InstallAppMetadataTest
Change-Id: I95c611c71f978629ca1e7781e3515e2a67cceba6
3 files changed