chore(java_templates): add default CODEOWNERS files for samples reviews

.github/CODEOWNERS

@@ -0,0 +1,8 @@
+# Code owners file.
+# This file controls who is tagged for review for any given pull request.
+
+# For syntax help see:
+# https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners#codeowners-syntax
+
+# The java-samples-reviewers team is the default owner for samples changes
+samples/**/*.java       @googleapis/java-samples-reviewers

synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-core.git",
-        "sha": "e4a04a2486474fef30584c2067e0afd7f8dbb613"
+        "sha": "4df33f0da02855161562e80a9d50e52dc21f4693"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "5b48b0716a36ca069db3038da7e205c87a22ed19"
+        "sha": "8b65daa222d193b689279162781baf0aa1f0ffd2"
       }
     }
   ]