clearkey hidl: parsePssh securely

Bug: 137282168
Test: drmpoc
Change-Id: I480ee99778f8c774cb5b857b25c32d926270092d
Merged-In: I480ee99778f8c774cb5b857b25c32d926270092d
(cherry picked from commit 230f58c028f0840ee2aeabe5dd8e4eb800ecb2af)
1 file changed