Fix crash in ResStringPool
Fix crash in ResStringPool

When a String isn't found in the StringPool,
we should not try to construct a String8 object
from the NULL string.

Bug:15163956
Change-Id: I51e701918b10a72c18a860b8a36dce2afd9c0b82

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base