Change the app compat check for mutable implicit pending intents

The old check takes the changeID and the UID which will only consider
the minimum targetSDK amongst the packages in that sharedUID. The new
check will specifically target the package which means that other
packages with lower targetSDKs on the sharedUID won't affect it.

Bug: 280435600
Test: atest PendingIntentTest
Test: manually with a lower targetSDK
Test: manually with a debugger as the system_server
Change-Id: Icb3154048660f5891c403ee5037124d3a7b78de3