Replace getContext with getTargetContext.

We only care about the target's cache dir. etc. and not
the test code's.

bug: 19718724

(cherry picked from commit 7ba40983eec5794a9598022f32a302d05b78fa71)

Change-Id: Icd18f2b9022328fcbc12e891e9729ce0b5fed66e
1 file changed