Add temporary cache dir. Need to change to Java call.

platform/android/cache_database_data.cpp

@@ -0,0 +1,13 @@
+#include <mbgl/platform/platform.hpp>
+
+namespace mbgl {
+namespace platform {
+
+// Returns the path to the default cache database on this system.
+std::string defaultCacheDatabase() {
+// TODO need to use get cache dir from java
+    return "/data/data/com.mapbox.mapboxgl.app/mbgl-cache.db";
+}
+
+}
+}