Update git submodules

* Update frameworks/support from branch 'androidx-main'
  to 34b7b19567c197ee46aa18716e2f4a57127bfcff
  - Merge "agents: Add gob_vcs plugin and remove previous CoG instructions" into androidx-main
  - agents: Add gob_vcs plugin and remove previous CoG instructions
    
    Register the gob_vcs skill plugin from PDEIO in
    .agents/plugins.json so agents load the shared Git-on-Borg VCS plugin
    directly from Google3 when available.
    
    Remove raw git-citc instructions from manage_commits and
    manage_cl_workspaces in favor of gob_vcs, while keeping existing
    repo/git instructions for standard checkouts.
    
    Tested:
    * "Using manage_cl_workspaces, build :core:core-telecom with PROJECT_PREFIX=:core in the isolated workspace and verify that output artifacts are written to ~/androidxout/cl_<conv_id>."
    * "Sync the isolated workspace cleanly to Gerrit change aosp/4335615 using cl_session_setup.py sync --clean and inspect the commit graph and modified files in the isolated workspace using gob_vcs."
    * "Using manage_cl_workspaces, manage_commits, and gob_vcs, provision an isolated CoG workspace, add a doc file at docs/test_scoping.md explaining how to scope Compose builds using PROJECT_PREFIX, and describe the local commit in the isolated workspace following AndroidX commit message conventions."
    Change-Id: Ie46f1aa428f6e54a5e23bf84a7ee0e4b74d7df2e