BigQuery: Add "managing datasets" snippets.

[tswast]

Add update ACLs sample. Add update dataset expiration sample. To be included in the docs at https://cloud.google.com/bigquery/docs/managing-datasets

P.S.

I had a little trouble with the javadoc snippets script not finding the method, so I added a little logic to detect possible duplicate definitions. In this case the script was catching a usage of the method rather than the definition.

[tswast]

Note: tests pass locally.

$ mvn -Dtest=ITDatasetInfoSnippets test
[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for com.google.cloud:google-cloud-examples:jar:0.46.1-alpha-SNAPSHOT
[WARNING] Reporting configuration should be done in <reporting> section, not in maven-site-plugin <configuration> as reportPlugins parameter.
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
[INFO] Inspecting build with total of 1 modules...
[INFO] Installing Nexus Staging features:
[INFO]   ... total of 1 executions of maven-deploy-plugin replaced with nexus-staging-maven-plugin
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Google Cloud Examples 0.46.1-alpha-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-enforcer-plugin:3.0.0-M1:enforce (enforce) @ google-cloud-examples ---
[INFO]
[INFO] --- maven-checkstyle-plugin:2.17:check (checkstyle) @ google-cloud-examples ---
[INFO] Starting audit...
Audit done.
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ google-cloud-examples ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/swast/src/google-cloud-java/google-cloud-examples/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.5.1:compile (default-compile) @ google-cloud-examples ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 70 source files to /Users/swast/src/google-cloud-java/google-cloud-examples/target/classes
[WARNING] bootstrap class path not set in conjunction with -source 1.7
[WARNING] /Users/swast/src/google-cloud-java/google-cloud-examples/src/main/java/com/google/cloud/examples/translate/TranslateExample.java:[187,21] setApiKey(java.lang.String) in com.google.cloud.translate.TranslateOptions.Builder has been deprecated
[WARNING] /Users/swast/src/google-cloud-java/google-cloud-examples/src/main/java/com/google/cloud/examples/storage/snippets/StorageSnippets.java:[157,24] create(com.google.cloud.storage.BlobInfo,java.io.InputStream,com.google.cloud.storage.Storage.BlobWriteOption...) in com.google.cloud.storage.Storage has been deprecated
[WARNING] /Users/swast/src/google-cloud-java/google-cloud-examples/src/main/java/com/google/cloud/examples/storage/snippets/StorageSnippets.java:[177,24] create(com.google.cloud.storage.BlobInfo,java.io.InputStream,com.google.cloud.storage.Storage.BlobWriteOption...) in com.google.cloud.storage.Storage has been deprecated
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ google-cloud-examples ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.5.1:testCompile (default-testCompile) @ google-cloud-examples ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 20 source files to /Users/swast/src/google-cloud-java/google-cloud-examples/target/test-classes
[WARNING] bootstrap class path not set in conjunction with -source 1.7
[INFO]
[INFO] --- maven-surefire-plugin:2.19.1:test (default-test) @ google-cloud-examples ---

-------------------------------------------------------
 T E S T S
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Running com.google.cloud.examples.bigquery.snippets.ITDatasetInfoSnippets
Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 4.427 sec - in com.google.cloud.examples.bigquery.snippets.ITDatasetInfoSnippets

Results :

Tests run: 2, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 12.736 s
[INFO] Finished at: 2018-05-03T15:34:01-07:00
[INFO] Final Memory: 41M/535M
[INFO] ------------------------------------------------------------------------