Do not clear activity type in clearSizeCompatMode

The activity type was set when adding the activity to a task, so
reseting activity type in clearSizeCompatMode might leaving it undefined
because the activity is already added to a task.

Fix: 267559999
Test: atest SizeCompatTests
Change-Id: I611a5e98124937b7056b02cdedfe3884f99c3218
1 file changed