This is the 2nd attempt to merge restartInput into startInput in
internal IPC after fixing the mistake in new parameter order in
the previous CL [1].
As a preparation to start tracking all the event flows that
cause InputMethodManagerService#setImeWindowStatus(), this CL
merges an internal IPC method IInputMethod#restartInput() into
IInputMethod#startInput() in favor of simplicity.
This is a refactoring CL that should have no behavior change.
[1]: Ifda6f74ac1b1370d9e9a9fe60354b692121fdcb9
1a5838e966
Test: Set true to InputMethodService#DEBUG and make sure startInput()
and restartInput() are called in the following scenario.
1. Complete the setup wizard.
2. adb shell am start -a android.app.action.SET_NEW_PASSWORD
3. Proceed to "Choose your password" page
4. Make sure startInput() gets called.
5. Type "aaaa" then hit "CONTINUE" button.
6. Make sure restartInput() gets called.
Bug: 35079353
Change-Id: I476d0cf8cbb0a0134941854f9337d9ad15e66a71
f7526b5896