Remove unnecessary FlaggedApi annotation from Layout.getText()

The `FlaggedApi` annotation must only be used for new APIs but
`Layout.getText()` has been in the public API since Android was first
checked into Android.

Bug: 304989985
Test: m checkapi
Change-Id: I7ae98f9495abffa1e483cae86c8d6f6ae2a400d9
2 files changed