Update git submodules

* Update frameworks/support from branch 'androidx-main'
  to b70c9eabfb776b0180788287f39cd2e0a3ba7804
  - Merge "Enable common-custom-user-data-grade-plugin for main project" into androidx-main
  - Enable common-custom-user-data-grade-plugin for main project
    
    This will record additional values such as git state, invocation
    from commandline vs studio, etc.
    
    Test: ./gradlew tasks -> https://ge.androidx.dev/s/c4fgrgeorwply/custom-values
    Change-Id: I365f932aa2864bea1f3fca8911f59ad0624c69ec
    

* Update prebuilts/androidx/external from branch 'androidx-main'
  to 39efe914d56032314b27de3dc7c1f507019b01dd
  - Merge "Add common-custom-user-data-gradle-plugin prebuilts." into androidx-main
  - Add common-custom-user-data-gradle-plugin prebuilts.
    
    Test: None
    Change-Id: If818023e1a038acbc6b506a5ece0ef701a3a2c2f