Camera: Save 1 frame time for takePicture call

Move the latest request signal call right before submitting request to HAL,
which avoids unnecessary 1 frame time wait.

Also fix request status constructor issue, and the log tag for Camera2Client.

Bug: 10570497
Change-Id: I0b1818658bee9983b117e49a5a00f1aab515c567
3 files changed