Checking whether ComponentName with current InputMethod is not null

Summary : Sometime Settings.Secure.DEFAULT_INPUT_METHOD may actually not be set or set wrongly and that may actually cause unflattenFromString to return null.

Test: Build passes

Change-Id: I86c6cb9a32ebbeb7cb09730c9888e756f49b2b37
Signed-off-by: Abhishek Gadewar <abhishekgadewar@meta.com>