ci: prepare Release Please for 7.0.x-lts branch

Author: suztomo

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+    "boms/cloud-lts-bom": "7.0.1"
+}

boms/cloud-lts-bom/pom.xml

@@ -7,7 +7,7 @@
 
   <groupId>com.google.cloud</groupId>
   <artifactId>gcp-lts-bom</artifactId>
-  <version>7.0.2-SNAPSHOT</version>
+  <version>7.0.2-SNAPSHOT</version><!-- {x-version-update:gcp-lts-bom:current} -->
   <packaging>pom</packaging>
 
   <name>Google Cloud Long Term Support BOM</name>
@@ -500,5 +500,51 @@
       </dependency>
     </dependencies>
   </dependencyManagement>
-
+  <profiles>
+    <profile>
+      <id>release</id>
+      <activation>
+        <property>
+          <name>performRelease</name>
+        </property>
+      </activation>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-gpg-plugin</artifactId>
+            <version>3.2.7</version>
+            <executions>
+              <execution>
+                <id>sign-artifacts</id>
+                <phase>verify</phase>
+                <goals>
+                  <goal>sign</goal>
+                </goals>
+                <configuration>
+                  <gpgArguments>
+                    <arg>--pinentry-mode</arg>
+                    <arg>loopback</arg>
+                  </gpgArguments>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-source-plugin</artifactId>
+            <version>3.3.1</version>
+            <executions>
+              <execution>
+                <id>attach-sources</id>
+                <goals>
+                  <goal>jar-no-fork</goal>
+                </goals>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
 </project>

boms/cloud-lts-bom/versions.txt

@@ -0,0 +1,4 @@
+# Format:
+# module:released-version:current-version
+
+gcp-lts-bom:7.0.1:7.0.2-SNAPSHOT

release-please-config.json

@@ -0,0 +1,12 @@
+{
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "separate-pull-requests": true,
+  "include-component-in-tag": true,
+  "packages": {
+    "boms/cloud-lts-bom": {
+        "component": "gcp-lts-bom",
+        "release-type": "java-yoshi"
+    }
+  },
+  "bootstrap-sha": "6b9240114536a03b72929d5fade85599fbdbbdd0"
+}