Remove unused resources

java/res/drawable-mdpi/key_hint_larger_holo.9.png

java/res/drawable-mdpi/key_hint_minus_holo.9.png

java/res/drawable-mdpi/key_hint_minus_large_holo.9.png

java/res/drawable-mdpi/key_hint_parenclose_holo.9.png

java/res/drawable-mdpi/key_hint_parenopen_holo.9.png

java/res/drawable-mdpi/key_hint_period_holo.9.png

java/res/drawable-mdpi/key_hint_semicolon_holo.9.png

java/res/drawable-mdpi/key_hint_simplequote_holo.9.png

java/res/drawable-mdpi/key_hint_slash_holo.9.png

java/res/drawable-mdpi/key_hint_slash_large_holo.9.png

java/res/drawable-mdpi/key_hint_smaller_holo.9.png

java/res/drawable-mdpi/key_hint_star_holo.9.png

java/res/drawable-mdpi/key_hint_underscore_holo.9.png

java/res/drawable-mdpi/key_hint_underscore_large_holo.9.png

java/res/drawable-mdpi/keyboard_hint_at.9.png

java/res/drawable-mdpi/keyboard_hint_colon.9.png

java/res/drawable-mdpi/keyboard_hint_doublecross.9.png

java/res/drawable-mdpi/keyboard_hint_exclamation.9.png

java/res/drawable-mdpi/keyboard_hint_greater.9.png

java/res/drawable-mdpi/keyboard_hint_plus.9.png