Android: also update APP_PLATFORM to android-16 in Application.mk

https://hg.libsdl.org/SDL/rev/8db358c7a09a
https://hg.libsdl.org/SDL/rev/787e86a461f5
diff --git a/android-project/app/jni/Application.mk b/android-project/app/jni/Application.mk
index 15b2a73..023bc20 100644
--- a/android-project/app/jni/Application.mk
+++ b/android-project/app/jni/Application.mk
@@ -7,4 +7,4 @@
 APP_ABI := armeabi-v7a arm64-v8a x86 x86_64
 
 # Min runtime API level
-APP_PLATFORM=android-14
+APP_PLATFORM=android-16