Track the number of PendingIntent per UID

Log a warning if there are too many PendingIntent from a UID

Bug: 148238407
Bug: 159460420
Test: Manual - Get & release tons of PendingIntent, check the logs
Test: atest \
FrameworksMockingServicesTests: com.android.server.am.PendingIntentControllerTest
Change-Id: I47d2c7c3557be352b1af6c957067e9418a24ced2