Always enable backpressure propagation during GPU composition

Change I54f1bd6074e27fb6e00d8397a704fc1d5f1ddd35 relaxed the condition
enabling backpressure propagation to be in all cases where device
composition was performed. This change re-tightens that condition so
that propagation is never enabled when GPU composition is performed.

Bug: 131134223
Test: systrace
Change-Id: If89aae62dc362ca0e471439a26c211acca5184f1