fix(java): exclude unused dependencies from gax-grpc (#721)

* fix(java): exclude unused dependencies from gax-grpc

google-cloud-compute/pom.xml

@@ -37,10 +37,73 @@
     </dependency>
 
     <!-- gax-grpc brings in Protobuf reflection configurations which are needed
-    for native image compilation. -->
+    for native image compilation. Excluding gax-grpc dependencies since they are not
+    needed for standard Java and native-image users.  -->
     <dependency>
       <groupId>com.google.api</groupId>
       <artifactId>gax-grpc</artifactId>
+      <exclusions>
+        <exclusion>
+          <groupId>com.google.api</groupId>
+          <artifactId>api-common</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.google.api</groupId>
+          <artifactId>api-common</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.google.api.grpc</groupId>
+          <artifactId>proto-google-common-protos</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.google.auth</groupId>
+          <artifactId>google-auth-library-credentials</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.google.guava</groupId>
+          <artifactId>guava</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-api</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>org.threeten</groupId>
+          <artifactId>threetenbp</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.google.auth</groupId>
+          <artifactId>google-auth-library-oauth2-http</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-alts</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-auth</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-protobuf</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-stub</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-netty-shaded</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>io.grpc</groupId>
+          <artifactId>grpc-googleapis</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.google.code.findbugs</groupId>
+          <artifactId>jsr305</artifactId>
+        </exclusion>
+      </exclusions>
     </dependency>
 
     <dependency>