Few code paths were still using the AMS lock which would cause races
corrupting PendingIntentRecord data.
Test: Builds. Existing pending intent tests pass:
atest CtsAppTestCases:android.app.cts.PendingIntentTest
Bug: 134707863
Change-Id: If55c0df1a24b50e72eb38f24d69a5a4aa1e8bfb3