chore: regenerate common templates (#307)

* changes without context

        autosynth cannot find the source of changes triggered by earlier changes in this
        repository, or by version upgrades to tools such as linters.

* chore(java): enable generated-files-bot

This bot will comment on pull requests that modify templated files. For java, we configure to read from our 2 synth.metadata files: (primary templates and README)

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Fri Oct 30 14:22:02 2020 -0700
Source-Repo: googleapis/synthtool
Source-Sha: b19b401571e77192f8dd38eab5fb2300a0de9324
Source-Link: googleapis/synthtool@b19b401

Author: yoshi-automation

.github/CODEOWNERS

@@ -9,4 +9,4 @@
 **/*.java               @googleapis/api-logging
 
 # The java-samples-reviewers team is the default owner for samples changes
-samples/**/*.java       @googleapis/java-samples-reviewers @googleapis/api-logging
+samples/**/*.java       @googleapis/java-samples-reviewers

.github/generated-files-bot.yml

@@ -0,0 +1,7 @@
+externalManifests:
+- type: json
+  file: 'synth.metadata'
+  jsonpath: '$.generatedFiles[*]'
+- type: json
+  file: '.github/readme/synth.metadata/synth.metadata'
+  jsonpath: '$.generatedFiles[*]'

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-logging.git",
-        "sha": "c2d16da4417da049af0c78f779c18163f985618b"
+        "sha": "71e30f69e60d93fa4074cd254bcebb8e7eb6e9b8"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "f68649c5f26bcff6817c6d21e90dac0fc71fef8e"
+        "sha": "b19b401571e77192f8dd38eab5fb2300a0de9324"
       }
     }
   ],
@@ -40,6 +40,7 @@
     ".github/ISSUE_TEMPLATE/feature_request.md",
     ".github/ISSUE_TEMPLATE/support_request.md",
     ".github/PULL_REQUEST_TEMPLATE.md",
+    ".github/generated-files-bot.yml",
     ".github/readme/synth.py",
     ".github/release-please.yml",
     ".github/snippet-bot.yml",