hide game cover in android gallery

Source/Core/Common/CommonPaths.h

@@ -22,6 +22,7 @@
 #elif defined ANDROID
 #define USERDATA_DIR "user"
 #define DOLPHIN_DATA_DIR "/sdcard/dolphin-emu"
+#define NOMEDIA_FILE ".nomedia"
 #else
 #define USERDATA_DIR "user"
 #define DOLPHIN_DATA_DIR "dolphin-emu"

Source/Core/UICommon/UICommon.cpp

@@ -178,6 +178,8 @@ void CreateDirectories()
 #ifndef ANDROID
   File::CreateFullPath(File::GetUserPath(D_THEMES_IDX));
   File::CreateFullPath(File::GetUserPath(D_STYLES_IDX));
+#else
+  File::CreateEmptyFile(File::GetUserPath(D_COVERCACHE_IDX) + DIR_SEP NOMEDIA_FILE);
 #endif
 }