libhwjpeg: Move cleanup to destructor Bug: 318122042 Test: gca_smoke.py (cherry picked from https://googleplex-android-review.googlesource.com/q/commit:0368ff7d82491f541250e90ca55de0875db70777) Merged-In: Ie191e1079a3e16b5ce7d7f6608a67c39cbe81fc8 Change-Id: Ie191e1079a3e16b5ce7d7f6608a67c39cbe81fc8