This method, and the corresponding system property
persist.sys.ime.can_render_gestural_nav_buttons were originally added
in [1], just before starting the implementation of gesture navigation
handling for IMEs. These were meant to serve as a feature flag,
initially turned off, and later permanently enabled.
This removes the sysprop and the code path handling it being disabled.
[1]: I7a2e9f08072a97d61b78dddb144282a5728d1407
Flag: EXEMPT refactor
Bug: 281029564
Bug: 411106486
Test: atest InputMethodServiceTest#testShowHideImeNavigationBar_doesDrawImeNavBar
InputMethodServiceTest#testShowHideImeNavigationBar_doesNotDrawImeNavBar
InputMethodServiceTest#testBackButtonClick
InputMethodServiceTest#testBackButtonLongClick
InputMethodServiceTest#testImeSwitchButtonClick
InputMethodServiceTest#testImeSwitchButtonLongClick
Change-Id: I94e2fb280a1dac130596d7f4e344d83cfc12b70e
Cosmin Băieș
7dedaeb255