surfaceflinger: Orient blur layer based on panel mount flip

As of CAF commit 1818975c,
surfaceflinger has support for rotated panel mounts.

Use the appropriate method to orient the blur layer based on it.

Commit 066aa860 reverted a piece
of code similar to this, since it was using the outdated methods
which broke compilation. Bring the code back, this time using
the appropriate method.

This partially reverts commit 066aa860.

Change-Id: I2a0272bb7fadef006f22290d21817f041d37883c