Add missing casts and remove FloatMath methods calls

[IriaSomobu]

This will remove compile errors on modern javac.

Note: android.util.FloatMath class was deprecated and all its methods was removed in API version 23 and above.

Also adding (Object) cast before bundle.getCollection() call will supress Incompatible types error in Android Studio.

[LingASDJ]

Good,But The Pixel Dungeon Not Update.

[IriaSomobu]

@LingASDJ yep, but maybe this code will help someone else