raphael: Explicitly disable "Enable GL comp backpressure"

When blur is enabled,
There is severe lag in; Launcher3 while scrolling apps in App drawer, Scrolling through recents and occasionally on QS pull down.

Enabling or completely removing the prop here sm6150-davinci/device_xiaomi_sm6150-common@d6233e0 doesn't seem to make an effect.
Explicitly disabling the "Enable GL comp backpressure" prop seems to slove the issue.

Lag & janks are gone now, even with blur.

Change-Id: Ia82d84d6ee867caa52ae93b72fbff132070bf808
Signed-off-by: helliscloser <mrumais@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

vendor.prop

@@ -143,8 +143,7 @@ vendor.gatekeeper.disable_spu=true
 
 # Graphics
 debug.renderengine.backend=skiaglthreaded
-debug.sf.disable_client_composition_cache=1
-debug.sf.enable_gl_backpressure=1
+debug.sf.enable_gl_backpressure=0
 debug.sf.early.sf.duration=16000000
 debug.sf.early.app.duration=16500000
 debug.sf.earlyGl.sf.duration=13500000