[RESTRICT AUTOMERGE] Careful with screenshots containing secure layers!

For purposes of	the screen rotation animation the system server	is allowed
to capture secure (not protected) layers and trusted not to persist screenshots
which may contain secure layers. However when displaying the screen rotation animation,
the layer the screenshot is placed on will itself not be secure, so if we record
the animation the recording will contain persisted versions of the secure content. Make sure
we use the new API from SurfaceFlinger to set FLAG_SECURE if our screenshot contains secure
content.

Bug: 69703445
Test: Transaction_test#SetFlagsSecureEUidSystem
Change-Id: I0dd36462867da52e6b1451f65f56c2c5d37538f3
(cherry picked from commit bab740f1)