GitLab

"adb shell cmd" always return 0 even though when cmd returns
non-zero.  Fix those instance of adb whose return values are checked
to call adb_var_shell* instead.

Without this fix, "adb shell test -e /system/bin/app_process32" always
return 0 on pre-L devices, and causes ndk-gdb to use the non-existance
app_process32 and fail

Change-Id: I1e8925dc989009859cf5c02a2fb92655864f1d7b