Use OpenGL skia (!= skiagl) on PowerVR Rogue GE8100

cf https://github.com/phhusson/treble_experimentations/issues/173

Change-Id: Ie796f701143ee926756d8803d930c7625afa73e6
diff --git a/rw-system.sh b/rw-system.sh
index c0c806a..552d86b 100644
--- a/rw-system.sh
+++ b/rw-system.sh
@@ -140,4 +140,7 @@
 
 mount -o bind /system/phh/empty /vendor/overlay/SysuiDarkTheme/SysuiDarkTheme.apk || true
 
+if grep -qF 'PowerVR Rogue GE8100' /vendor/lib/egl/GLESv1_CM_mtk.so;then
+	setprop debug.hwui.renderer opengl
+fi