Handle embedding startActivity Intent when calling from application

Before, we only resolve the Intent if it is called with Activity
context, which skip handling cross-process embedding if the
startActivity is called with Application context.

Now, when startActivity is called with Application context, we will
check if the Intent should be embedded in the known Task in the
organizer process.

Bug: 244411454
Test: atest WMJetpackUnitTests:SplitControllerTest
Change-Id: Ic1ee4f23330b4ce35888c0eabd1ee8eb13d13140