Deprecate UiAutomation#injectInputEvent for CTS tests

For input event injection, CTS tests should rely on uinput
(com.android.cts.input.UinputDevice), hid devices
(com.android.cts.input.HidDevice), or InjectInputInProcess
 * (com.android.cts.input.InjectInputInProcess) for in-process
   injection.

Bug: 277261245
Test: m
Flag:  com.android.input.flags.deprecate_uiautomation_input_injection
Change-Id: I83c82c16c4b43236c2bcd562c3d2178488dcdd48