Revert "[infra] Roll clang to match the version used by Flutter"

build/toolchain/android/BUILD.gn

Index: build/toolchain/android/BUILD.gn
diff --git a/build/toolchain/android/BUILD.gn b/build/toolchain/android/BUILD.gn
index 90e1256da8018fea3cc0291148fcf58c82370024..5e4847349d11342271e9d3ed8f7737de1e5f5372 100644
--- a/build/toolchain/android/BUILD.gn
+++ b/build/toolchain/android/BUILD.gn
@@ -47,16 +47,7 @@ template("android_gcc_toolchain") {
 
     is_clang = invoker.is_clang
     if (is_clang) {
-      host_suffix = ""
-      if (host_os == "linux") {
-        host_suffix = "x86_64-linux"
-      } else if (host_os == "mac") {
-        host_suffix = "x86_64-darwin"
-      } else {
-        assert(false, "Unknown host")
-      }
-
-      prefix = rebase_path("//buildtools/toolchain/clang+llvm-$host_suffix/bin",
+      prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
                            root_build_dir)
 
       cc = compiler_prefix + prefix + "/clang"