Use EmptyArray.STRING in Splitter.fastSplit().

This is a minor cleanup after
  https://android-review.googlesource.com/47964

Change-Id: Id8de6c09f3397b044082c275095ff7a7a43185f9
Fix compilation of Enum on JDK 7

Change-Id: I2e58b6a527e4ef1fc7ed3359b8aea88d01a031fb
Merge remote-tracking branch 'origin/cm-10.1' into cm-10.1-linaro