deps: update core dependencies (#24)

* deps: update core dependencies

* deps: import protobuf-bom

* deps: fix pom

Co-authored-by: Jeff Ching <chingor@google.com>

pom.xml

@@ -66,8 +66,8 @@
     <google.core.version>1.91.1</google.core.version>
     <google.api-common.version>1.8.1</google.api-common.version>
     <google.common-protos.version>1.17.0</google.common-protos.version>
-    <gax.version>1.50.1</gax.version>
-    <grpc.version>1.25.0</grpc.version>
+    <gax.version>1.52.0</gax.version>
+    <grpc.version>1.26.0</grpc.version>
     <protobuf.version>3.11.1</protobuf.version>
     <junit.version>4.12</junit.version>
     <guava.version>28.1-android</guava.version>
@@ -132,12 +132,14 @@
         <type>pom</type>
         <scope>import</scope>
       </dependency>
-
       <dependency>
         <groupId>com.google.protobuf</groupId>
-        <artifactId>protobuf-java</artifactId>
+        <artifactId>protobuf-bom</artifactId>
         <version>${protobuf.version}</version>
+        <type>pom</type>
+        <scope>import</scope>
       </dependency>
+
       <dependency>
         <groupId>com.google.api</groupId>
         <artifactId>api-common</artifactId>
@@ -166,7 +168,7 @@
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-core</artifactId>
-        <version>1.91.3</version>
+        <version>1.92.0</version>
       </dependency>
 
       <dependency>