Don't use shader disk cache on emulator

bug: 71900691

Emulator user might switch renderers, migrate a snapshot to a different
machine with a different shader binary format, etc.

Plus, program binaries don't seem to work so well on some desktop GPUs.

Change-Id: I0c6239acbd556097494aa903d6603c963d3141cb
diff --git a/libs/hwui/Properties.h b/libs/hwui/Properties.h
index af4b694..179b97b 100644
--- a/libs/hwui/Properties.h
+++ b/libs/hwui/Properties.h
@@ -180,6 +180,11 @@
  */
 #define PROPERTY_CAPTURE_SKP_FILENAME "debug.hwui.skp_filename"
 
+/**
+ * Property for whether this is running in the emulator.
+ */
+#define PROPERTY_QEMU_KERNEL "ro.kernel.qemu"
+
 ///////////////////////////////////////////////////////////////////////////////
 // Misc
 ///////////////////////////////////////////////////////////////////////////////
@@ -261,6 +266,8 @@
     // Used for testing only to change the render pipeline.
     static void overrideRenderPipelineType(RenderPipelineType);
 
+    static bool runningInEmulator;
+
 private:
     static ProfileType sProfileType;
     static bool sDisableProfileBars;