Add cache path variable from Java

Use cache path for db location
Add Assetbridge to extract asset files to cache path
Fix SSL by using extracted ca bundle
Use file:// style URL using extracted styles

platform/android/cache_database_data.cpp

@@ -1,4 +1,5 @@
 #include <mbgl/platform/platform.hpp>
+#include "../../android/cpp/NativeMapView.hpp"
 
 namespace mbgl {
 namespace platform {
@@ -6,7 +7,7 @@ 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";
+    return mbgl::android::cache_path + "/mbgl-cache.db";
 }
 
 }