Update the Javadoc for the edge-to-edge enforcement

This CL deprecates APIs as follows:
R.attr#enforceStatusBarContrast
R.attr#statusBarColor
R.attr#navigationBarColor
R.attr#navigationBarDividerColor
Window#isStatusBarContrastEnforced
Window#setStatusBarContrastEnforced
Window#setDecorFitsSystemWindows
Window#setStatusBarColor
Window#setNavigationBarColor
Window#setNavigationBarDividerColor
Window#getStatusBarColor
Window#getNavigationBarColor
Window#getNavigationBarDividerColor

This CL also creates an API for apps to opt-out:
R.attr#windowOptOutEdgeToEdgeEnforcement

Bug: 309578419
Test: atest PhoneWindowTest
Change-Id: I73abd3a075276440afdf7e9da6745638b68d51ce