samples: add presubmit lint check

* 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_templates): add lint/static analysis presubmit checks for samples

* chore(java_templates): add lint/static analysis presubmit checks for samples

* chore: fix trailing whitespace

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Mon Aug 17 14:29:16 2020 -0700
Source-Repo: googleapis/synthtool
Source-Sha: c3caf0704f25a0c365f1c315e804a30b87c62a75
Source-Link: googleapis/synthtool@c3caf07

* chore(java_templates): stop running pmd/spotbugs checks for samples

This was creating too much noise. We will revisit with other options and/or tune these checks.

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Wed Aug 19 12:26:49 2020 -0700
Source-Repo: googleapis/synthtool
Source-Sha: 9602086c6c5b05db77950c7f7495a2a3868f3537
Source-Link: googleapis/synthtool@9602086

Author: yoshi-automation

.github/workflows/samples.yaml

@@ -0,0 +1,14 @@
+on:
+  pull_request:
+name: samples
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 8
+      - name: Run checkstyle
+        run: mvn -P lint --quiet --batch-mode checkstyle:check
+        working-directory: samples/snippets

README.md

@@ -17,7 +17,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>libraries-bom</artifactId>
-      <version>9.0.0</version>
+      <version>9.1.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-containeranalysis.git",
-        "sha": "14bb9d3a1c70bf2823ea0e70ce1f3f8837a3031a"
+        "sha": "9284998ec59114d875a84df00982110e3aa9084f"
       }
     },
     {
@@ -27,7 +27,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "f8823dec98277a9516f2fb6fae9f58b3a59a23e1"
+        "sha": "9602086c6c5b05db77950c7f7495a2a3868f3537"
       }
     }
   ],
@@ -60,6 +60,7 @@
     ".github/release-please.yml",
     ".github/trusted-contribution.yml",
     ".github/workflows/ci.yaml",
+    ".github/workflows/samples.yaml",
     ".kokoro/build.bat",
     ".kokoro/build.sh",
     ".kokoro/coerce_logs.sh",