No longer restrict to -source 1.5 since it causes a warning with 1.7

(cherry picked from commit e17838ffedee1796920636c2f99c933aa1ce4b3c)

Change-Id: Ied11738da9621280185a62f267a5d527e6ed927b
Merge "No longer restrict to -source 1.5 since it causes a warning with 1.7"