Turn on Android platform

Bug: b/122837488
Change-Id: I1d4b33943ea68db3c068b604876745ba6fb5097c
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/30188
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Tested-by: Hernan Liatis <hliatis@google.com>
diff --git a/Android.bp b/Android.bp
index 9a6f9c1..4b75345 100644
--- a/Android.bp
+++ b/Android.bp
@@ -29,6 +29,7 @@
 
     cppflags: [
         "-Woverloaded-virtual",
+        "-DVK_USE_PLATFORM_ANDROID_KHR",
     ],
     cpp_std: "c++11",