ITS: adjust sleep time in scene_low_light

Remove the sleep between the 3A convergence and the photo capture to
avoid the 3A convergence data from becoming outdated.

Add the sleep after changing the light condition.

Test: tested on Pixel devices
Bug: 433891257
Flag: TEST_ONLY
Change-Id: I0e95a5afa29b180c56e11912319d759503492f44
2 files changed