Migrate from legacy com.google.gwt to org.gwtproject.

org.gwtproject starts being available at the 2.10.0 release, so upgrade to that where necessary.

See google/auto#1342 (comment)

RELNOTES=n/a
PiperOrigin-RevId: 457020479

guava-gwt/pom.xml

@@ -17,7 +17,7 @@
  This project includes GWT-friendly sources.
  </description>
  <properties>
- <gwt.version>2.9.0</gwt.version>
+ <gwt.version>2.10.0</gwt.version>
  <gwt.plugin.version>2.8.2</gwt.plugin.version>
  <gwt.logLevel>WARN</gwt.logLevel>
  </properties>
@@ -78,13 +78,13 @@
  <scope>test</scope>
  </dependency>
  <dependency>
- <groupId>com.google.gwt</groupId>
+ <groupId>org.gwtproject</groupId>
  <artifactId>gwt-dev</artifactId>
  <version>${gwt.version}</version>
  <scope>provided</scope>
  </dependency>
  <dependency>
- <groupId>com.google.gwt</groupId>
+ <groupId>org.gwtproject</groupId>
  <artifactId>gwt-user</artifactId>
  <version>${gwt.version}</version>
  <scope>test</scope>
@@ -315,6 +315,7 @@
  </execution>
  </executions>
  </plugin>
+ <!-- TODO(cpovirk): We really should try tbroyer's plugin instead of this legacy one. -->
  <plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>gwt-maven-plugin</artifactId>