Update git submodules

* Update tools/repohooks from branch 'master'
  to e0447aa1766a3e1cb73c82c41ff9d411d45b57fb
  - clang-format: handle exit(0) w/no output from git-clang-format
    
    Add a unittest to start checking the random behaviors that the tool
    likes to use.
    
    Bug: 229737306
    Test: unittests
    Change-Id: I5156eebbb133017202058c82e61790be0b3fa0b3
    
diff --git a/tools/repohooks b/tools/repohooks
index 5722c92..e0447aa 160000
--- a/tools/repohooks
+++ b/tools/repohooks
@@ -1 +1 @@
-Subproject commit 5722c9210732f28d5947067b0387916bf9a44ad7
+Subproject commit e0447aa1766a3e1cb73c82c41ff9d411d45b57fb