Using the "test" GN template instead of the "ios_xctest_test" one we will get iOS support for isolates via MB and GN for free, making it easier to migrate the iOS recipe and fix bugs.webrtc.org/11604. Bug: webrtc:11881 Change-Id: I72b90f8494c473fa567e6296caf7a771e4caba92 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/182680 Reviewed-by: Dirk Pranke <dpranke@google.com> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#32064}