[lldb][test_suite] Fix skipIfTargetAndroid decorator

Summary:
Delete the duplicate func skipIfTargetAndroid
Fix the old one. It didn't work for missing an argument bugnumber, this somehow made the decorator failed

Differential Revision: https://reviews.llvm.org/D64583

Patch by Wanyi Ye <kusmour@gmail.com>

llvm-svn: 366771