[general] moving ios and android project under ./platform folder

platform/android/src/image.cpp

@@ -0,0 +1,21 @@
+#include <mbgl/util/image.hpp>
+#include <mbgl/util/string.hpp>
+
+#include <string>
+
+#include "attach_env.hpp"
+#include "bitmap_factory.hpp"
+
+namespace mbgl {
+
+PremultipliedImage decodeImage(const std::string& string) {
+    auto env{ android::AttachEnv() };
+
+    auto array = jni::Array<jni::jbyte>::New(*env, string.size());
+    jni::SetArrayRegion(*env, *array, 0, string.size(),
+                        reinterpret_cast<const signed char*>(string.data()));
+
+    return android::Bitmap::GetImage(*env, android::BitmapFactory::DecodeByteArray(*env, array, 0, string.size()));
+}
+
+} // namespace mbgl