Fix: exit code is 0 even when check-boot-jars.py fails
Fix: exit code is 0 even when check-boot-jars.py fails

Fix the bug that build is still success when boot jars contain
non-whitelisted classes. Now, check-boot-jars.py correctly
finishes with exit code 1 when non-whitelisted classes are found.

Change-Id: Id5c80ef9fdb70213d878d569f6033be2c9eb90d3

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build