Update androidx-master-dev references to new androidx-main branch

Bug: 175313425
Test: N/A
Change-Id: I72dab29f3cf7028510bb7aba32930cf94b1644b7
diff --git a/fragment/README.md b/fragment/README.md
index 413f993..7ad2c0a 100644
--- a/fragment/README.md
+++ b/fragment/README.md
@@ -6,7 +6,7 @@
 
 [Release notes](https://developer.android.com/jetpack/androidx/releases/fragment)
 
-[Browse source](https://android.googlesource.com/platform/frameworks/support/+/androidx-master-dev/fragment/)
+[Browse source](https://android.googlesource.com/platform/frameworks/support/+/androidx-main/fragment/)
 
 [Reference documentation](https://developer.android.com/reference/androidx/fragment/app/package-summary)