Enabling bitcode doesn't seem to create a separate dSYM.
To make it work in this configuration, when creating an XCFramework,
pass dSYM only if it exists.
Bug: none
Change-Id: I6d95dc765accc10a70caeb88063d05eeea630dd1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/228700
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34762}