Use UICommon's game list code on Android

Deduplicates code, and gets rid of some problems the old code had
(such as: bad performance when calling native functions, only one
disc showing up for multi-disc games, Wii banners being low-res,
unnecessarily much effort being needed for adding more metadata).

Source/Android/jni/AndroidCommon/IDCache.cpp

@@ -0,0 +1,110 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "jni/AndroidCommon/IDCache.h"
+
+#include <jni.h>
+
+static constexpr jint JNI_VERSION = JNI_VERSION_1_6;
+
+static JavaVM* s_java_vm;
+
+static jclass s_native_library_class;
+static jmethodID s_display_alert_msg;
+
+static jclass s_game_file_class;
+static jfieldID s_game_file_pointer;
+static jmethodID s_game_file_constructor;
+
+static jclass s_game_file_cache_class;
+static jfieldID s_game_file_cache_pointer;
+
+namespace IDCache
+{
+JavaVM* GetJavaVM()
+{
+  return s_java_vm;
+}
+
+jclass GetNativeLibraryClass()
+{
+  return s_native_library_class;
+}
+
+jmethodID GetDisplayAlertMsg()
+{
+  return s_display_alert_msg;
+}
+
+jclass GetGameFileClass()
+{
+  return s_game_file_class;
+}
+
+jfieldID GetGameFilePointer()
+{
+  return s_game_file_pointer;
+}
+
+jmethodID GetGameFileConstructor()
+{
+  return s_game_file_constructor;
+}
+
+jclass GetGameFileCacheClass()
+{
+  return s_game_file_cache_class;
+}
+
+jfieldID GetGameFileCachePointer()
+{
+  return s_game_file_cache_pointer;
+}
+
+}  // namespace IDCache
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+jint JNI_OnLoad(JavaVM* vm, void* reserved)
+{
+  s_java_vm = vm;
+
+  JNIEnv* env;
+  if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION) != JNI_OK)
+    return JNI_ERR;
+
+  const jclass native_library_class = env->FindClass("org/dolphinemu/dolphinemu/NativeLibrary");
+  s_native_library_class = reinterpret_cast<jclass>(env->NewGlobalRef(native_library_class));
+  s_display_alert_msg = env->GetStaticMethodID(s_native_library_class, "displayAlertMsg",
+                                               "(Ljava/lang/String;Ljava/lang/String;Z)Z");
+
+  const jclass game_file_class = env->FindClass("org/dolphinemu/dolphinemu/model/GameFile");
+  s_game_file_class = reinterpret_cast<jclass>(env->NewGlobalRef(game_file_class));
+  s_game_file_pointer = env->GetFieldID(game_file_class, "mPointer", "J");
+  s_game_file_constructor = env->GetMethodID(game_file_class, "<init>", "(J)V");
+
+  const jclass game_file_cache_class =
+      env->FindClass("org/dolphinemu/dolphinemu/model/GameFileCache");
+  s_game_file_cache_class = reinterpret_cast<jclass>(env->NewGlobalRef(game_file_cache_class));
+  s_game_file_cache_pointer = env->GetFieldID(game_file_cache_class, "mPointer", "J");
+
+  return JNI_VERSION;
+}
+
+void JNI_OnUnload(JavaVM* vm, void* reserved)
+{
+  JNIEnv* env;
+  if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION) != JNI_OK)
+    return;
+
+  env->DeleteGlobalRef(s_native_library_class);
+  env->DeleteGlobalRef(s_game_file_class);
+  env->DeleteGlobalRef(s_game_file_cache_class);
+}
+
+#ifdef __cplusplus
+}
+#endif