Fix for reboot on connecting to TV through HDMI.

In LocalDisplayAdapter there is a code flow possibility for
activeColorTransform to be null, when the HAL does not support
color transforms. The Fix covers this code flow path to ensure
no framework reboot occurs due to NullPointerException, even if
the color transforms feature is not supported.

CRs-Fixed: 957125
Change-Id: Ifbadcc8f55e37ba78acc549198df0f0876bd0560