Inline 'reloadInputMethodStr' in InputMethodUtils.java

This is a mechanical code clean up for

  InputMethodSettings#appendAndPutEnabledInputMethodLocked(),

which always takes false in 'reloadInputMethodStr'.  We should be able
to safely inline that parameter without changing any existing
behavior.

Bug: 309837937
Test: presubmit
Change-Id: I804759db7727d3b0533b1d3c029d5bfc5370b374