Android Loading Tools: use computed adb path for cert install

adb_install_cert will use the system adb path if an adb path isn't
given. This will cause an adb error if whatever version of adb is installed
outside of chromium doesn't match what's in third_party/android_tools, as that
version of adb is used elsewhere.

Review-Url: https://codereview.chromium.org/2722113003
Cr-Original-Commit-Position: refs/heads/master@{#454224}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 7d02460714d56659a2901396bcf4e382d58fda2a
1 file changed