feat: integrate gapic generator change in googleapis (#220)

* 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.

* feat: integrate gapic generator change in googleapis

PiperOrigin-RevId: 308294748

Source-Author: Google APIs <noreply@google.com>
Source-Date: Fri Apr 24 11:44:16 2020 -0700
Source-Repo: googleapis/googleapis
Source-Sha: 28e76243c23cc282efbb288cb558c174e3e5e9ee
Source-Link: googleapis/googleapis@28e7624

README.md

@@ -20,7 +20,7 @@ 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>4.4.1</version>
+      <version>5.2.0</version>
       <type>pom</type>
       <scope>import</scope>
     </dependency>
@@ -41,7 +41,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigquerystorage</artifactId>
-  <version>0.128.1-beta</version>
+  <version>0.130.0-beta</version>
 </dependency>
 
 ```

synth.metadata

@@ -11,39 +11,39 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquerystorage.git",
-        "sha": "a0db93e9d1f714a68dd11ef38c782099701dd068"
+        "sha": "b80386394f3082e9695712343f37afc4d29df76f"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "d741cd976975c745d0199987aff0e908b8352992",
-        "internalRef": "305561906"
+        "sha": "28e76243c23cc282efbb288cb558c174e3e5e9ee",
+        "internalRef": "308294748"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "d741cd976975c745d0199987aff0e908b8352992",
-        "internalRef": "305561906"
+        "sha": "28e76243c23cc282efbb288cb558c174e3e5e9ee",
+        "internalRef": "308294748"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "d741cd976975c745d0199987aff0e908b8352992",
-        "internalRef": "305561906"
+        "sha": "28e76243c23cc282efbb288cb558c174e3e5e9ee",
+        "internalRef": "308294748"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "d741cd976975c745d0199987aff0e908b8352992",
-        "internalRef": "305561906"
+        "sha": "28e76243c23cc282efbb288cb558c174e3e5e9ee",
+        "internalRef": "308294748"
       }
     },
     {