Using LaunchActivity when possible

... to prevent race

In [1], we store ActivityClientRecord earlier to make
ActivityClientRecord accessible in onCreate Lifcycle callback.
However, we still store the activity after Activity#onCreate.

This CL fixes the exception by obtaining ActivityClientRecord
from launch Activity list first to prevent race.

fixes: 196900007
Test: Try reproducible steps several times and didn't see
the error log.

[1]: 85986bf9

Change-Id: I7553c56cad474feb73fca73c72b5e6e833b46fbf