chore: regenerate common templates (#309)

* 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): retry staging portion of the release with backoff

* chore(java): retry staging portion of the release with backoff

* build: skip logging the retried command - it may contain secrets

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Thu Nov 19 12:24:02 2020 -0800
Source-Repo: googleapis/synthtool
Source-Sha: 68742c6016bf0d16948a572633d17955a8737414
Source-Link: googleapis/synthtool@68742c6

* build(java): enable blunderbuss for samples

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Mon Nov 23 10:23:01 2020 -0800
Source-Repo: googleapis/synthtool
Source-Sha: 943bb78606d035001123030067dffcc34f4645f2
Source-Link: googleapis/synthtool@943bb78

.github/blunderbuss.yml

@@ -0,0 +1,7 @@
+# Configuration for the Blunderbuss GitHub app. For more info see
+# https://github.com/googleapis/repo-automation-bots/tree/master/packages/blunderbuss
+assign_prs_by:
+- labels:
+  - samples
+  to:
+  - googleapis/java-samples-reviewers

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-container.git",
-        "sha": "4ced51abb40d6ecaa45e0c8474bf52b604665f6b"
+        "sha": "7afc15aeab344efd38a3d6dda93ac50b048ca9f5"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "7fcc405a579d5d53a726ff3da1b7c8c08f0f2d58"
+        "sha": "943bb78606d035001123030067dffcc34f4645f2"
       }
     }
   ],
@@ -40,6 +40,7 @@
     ".github/ISSUE_TEMPLATE/feature_request.md",
     ".github/ISSUE_TEMPLATE/support_request.md",
     ".github/PULL_REQUEST_TEMPLATE.md",
+    ".github/blunderbuss.yml",
     ".github/generated-files-bot.yml",
     ".github/readme/synth.py",
     ".github/release-please.yml",