Issue was `getContentProcessesOomScore` was attempting to read other process's oom scores. This patch: * Adjusts `getContentProcessesOomScore` to read the oom score through the test privileged `uiAutomation` * Opens tests in `GeckoViewTest` gated by isolated process * Runs ktlint on `GeckoViewTest` Differential Revision: https://phabricator.services.mozilla.com/D246355