Rename gesture related classes

.../src/com/android/inputmethod/keyboard/PointerTracker.java

...tmethod/keyboard/internal/GestureStrokeDrawingParams.java

...tmethod/keyboard/internal/GestureStrokeDrawingPoints.java

...hod/keyboard/internal/GestureStrokeRecognitionParams.java

...hod/keyboard/internal/GestureStrokeRecognitionPoints.java

...utmethod/keyboard/internal/GestureTrailDrawingParams.java

...utmethod/keyboard/internal/GestureTrailDrawingPoints.java

...method/keyboard/internal/GestureTrailsDrawingPreview.java