SF: Ignore rounded corners if the layer can peek through

Bug: 163076219
Test: manual
Test: I53fc851eca876d44ba7cb9347f1c62d659c38932

In Layer::preparePerFrameCompositionState, no longer set
forceClientComposition to true based on the presence of rounded corners.
This will be determined later, based on whether the Layer will peek
through a Layer with a hole-punch.

In CachedSet::requiresHolePunch, return false if the layer must be
client composited for reasons other than rounded corners (which no
longer force client composition). While we could still use a hole punch,
it would not provide the desired effect (preventing waking up the GPU).

Add an extra field to overrideInfo, denoting whether this layer will
peek through another layer. Set it on a peekThroughLayer before sending
it to the HWC. If it's not set, and the layer has rounded corners, the
layer must be client composited, as before.

Change-Id: I3b4341d049c0fa5020dfd89ca9e765588a457eb1