Inline IMMS#resetAllInternalStateLocked()

Currently IMMS#resetAllInternalStateLocked(boolean, boolean) has
only two call sites, and the first parameter is the constant for
each call site.  We can get much simpler code by inlining the
method in question into those two call sites. It actually revealed
that UNBIND_REASON_RESET_IME should have been called
UNBIND_REASON_SWITCH_USER.

Test: no behavior change
Test: adb shell dumpsys input_method | grep "mMethodMapUpdateCount="
      to make sure that switching users can cause the same count
      increase.
Test: adb shell dumpsys input_method | grep "mMethodMapUpdateCount="
      to make sure that switching the device locale can cause the
      same count increase.
Bug: 35079353
Change-Id: I63388402369f58d11fdb21b508eb2051ff39fa5b