GalaxyParts: add 3MB cache setting & cleanup arrays

(cherry picked from commit d0a00ab2b4b1f807afeeba3c997afb8a46c497b2)

Change-Id: I07d29207b37d752581162077b0b33c6d317f29ff
Really use half-res bootanimation

Needs to be defined in common.mk so that vendor/cm can detect it.

Change-Id: Id4970b306cc4ce8d3a7e173db10728429e45b447
GalaxyParts: remove highend graphics option & don't set by default

No longer needed (see Settings -> Performance).

Change-Id: I9ba5fa6f07b2a64b8e5cead8312451747163ae2c
Disable extamp filter by default

Tired of people complaining about low volume and don't know
how to tweak the settings.

Change-Id: Ibfc397781cbb0161cc0c25e78d4b1b321acd3fff