Update git submodules

* Update external/lk from branch 'master'
  to 1b72f9136d34a7493a67e2290f30dfb6a800dbe7
  - [rust] Deny warnings by default
    
    Sets Rust to error on warnings, as we do for C/C++.
    
    Test: build.py
    Bug: 192309116
    Change-Id: I7d24df589a15313db39535d8ad56164b2d99d0cf
    

* Update trusty/user/base from branch 'master'
  to b168b3f8027f71a2fd4398fd95e03da1a028e9bb
  - [rust] libcompiler_builtins: Silence name collision
    
    To build the current version of compiler_builtins with -D warnings on we
    need to explicitly allow a name collision for i32::abs_diff until it is
    updated to explicitly use the fully qualified item path.
    
    Test: build.py
    Bug: 192309116
    Change-Id: I06038152d22cbd6b4512455a6338f498f5a09c53
    
diff --git a/external/lk b/external/lk
index cadfddf..1b72f91 160000
--- a/external/lk
+++ b/external/lk
@@ -1 +1 @@
-Subproject commit cadfddf1f586a2770f38729c0f2875166af26424
+Subproject commit 1b72f9136d34a7493a67e2290f30dfb6a800dbe7
diff --git a/trusty/user/base b/trusty/user/base
index 2d14243..b168b3f 160000
--- a/trusty/user/base
+++ b/trusty/user/base
@@ -1 +1 @@
-Subproject commit 2d14243be3e9cc0d350a43b6ea21260f884c452b
+Subproject commit b168b3f8027f71a2fd4398fd95e03da1a028e9bb