chore(spanner): update instance id (#3109)

Author: harshachinta

samples/install-without-bom/pom.xml

@@ -143,8 +143,8 @@
         <version>3.2.5</version>
         <configuration>
           <systemPropertyVariables>
-            <spanner.test.instance>java-client-integration-test</spanner.test.instance>
-            <spanner.test.instance.mr>java-client-mr-integration-test</spanner.test.instance.mr>
+            <spanner.test.instance>java-client-integration-tests</spanner.test.instance>
+            <spanner.test.instance.mr>java-client-mr-integration-tests</spanner.test.instance.mr>
             <spanner.test.instance.config>nam11</spanner.test.instance.config>
             <spanner.test.key.location>us-east1</spanner.test.key.location>
             <spanner.test.key.ring>java-client-integration-test-cmek-ring</spanner.test.key.ring>

samples/snapshot/pom.xml

@@ -142,8 +142,8 @@
         <version>3.2.5</version>
         <configuration>
           <systemPropertyVariables>
-            <spanner.test.instance>java-client-integration-test</spanner.test.instance>
-            <spanner.test.instance.mr>java-client-mr-integration-test</spanner.test.instance.mr>
+            <spanner.test.instance>java-client-integration-tests</spanner.test.instance>
+            <spanner.test.instance.mr>java-client-mr-integration-tests</spanner.test.instance.mr>
             <spanner.test.instance.config>nam11</spanner.test.instance.config>
             <spanner.test.key.location>us-east1</spanner.test.key.location>
             <spanner.test.key.ring>java-client-integration-test-cmek-ring</spanner.test.key.ring>

samples/snippets/pom.xml

@@ -178,8 +178,8 @@
         <version>3.2.5</version>
         <configuration>
           <systemPropertyVariables>
-            <spanner.test.instance>java-client-integration-test</spanner.test.instance>
-            <spanner.test.instance.mr>java-client-mr-integration-test</spanner.test.instance.mr>
+            <spanner.test.instance>java-client-integration-tests</spanner.test.instance>
+            <spanner.test.instance.mr>java-client-mr-integration-tests</spanner.test.instance.mr>
             <spanner.test.instance.config>nam11</spanner.test.instance.config>
             <spanner.test.key.location>us-east1</spanner.test.key.location>
             <spanner.test.key.ring>java-client-integration-test-cmek-ring</spanner.test.key.ring>