Update git submodules

* Update frameworks/support from branch 'androidx-master-dev'
  to b6d4a975ee8d52a83d19712cd452c6df66754428
  - Merge "ProgressIndicator polishing" into androidx-master-dev
  - ProgressIndicator polishing
    
    - Adds backgroundColor parameter for LinearProgressIndicators
    - Adds ProgressIndicatorConstants.DefaultProgressAnimationSpec as the default AnimationSpec that can be used when animating progress
    - Removes inner padding from CircularProgressIndicator
    - Coerces values outside the range 0f..1f into this range, instead of crashing at runtime
    
    Bug: b/161809914
    Bug: b/161804677
    Bug: b/144797733
    Test: ProgressIndicatorTest
    Relnote: "Added backgroundColor parameter to LinearProgressIndicator and removed internal padding from CircularProgressIndicator. Added new ProgressIndicatorConstants.DefaultProgressAnimationSpec which can be used as the default AnimationSpec when animating progress between values"
    Change-Id: If38b5dd58d052b75c1974031e0974f22808d9776
    
diff --git a/frameworks/support b/frameworks/support
index 61b83ac..b6d4a97 160000
--- a/frameworks/support
+++ b/frameworks/support
@@ -1 +1 @@
-Subproject commit 61b83aca602513030e86211f5b05c5995ab0438b
+Subproject commit b6d4a975ee8d52a83d19712cd452c6df66754428