Address warnings and Maven 4 incompatibilities.

RELNOTES=n/a
PiperOrigin-RevId: 969977222

android/guava-bom/pom.xml

@@ -66,6 +66,14 @@
 
   <build>
     <plugins>
+      <plugin>
+        <artifactId>maven-clean-plugin</artifactId>
+        <version>3.5.0</version>
+      </plugin>
+      <plugin>
+        <artifactId>maven-install-plugin</artifactId>
+        <version>3.1.4</version>
+      </plugin>
       <plugin>
         <groupId>org.sonatype.central</groupId>
         <artifactId>central-publishing-maven-plugin</artifactId>

android/guava-testlib/pom.xml

@@ -81,7 +81,7 @@
           <execution>
             <id>default-compile</id>
             <configuration>
-              <compilerArgs combine.children="append" combine.self="append">
+              <compilerArgs combine.children="append">
                 <arg>-XDignore.symbol.file</arg>
               </compilerArgs>
             </configuration>

android/guava/pom.xml

@@ -86,8 +86,8 @@
         </executions>
         <configuration>
           <instructions>
-            <!-- Silence a warning that claims that META-INF/versions/9/... is the "wrong directory" for our classes. -->
-            <_fixupmessages>^Classes found in the wrong directory: .*</_fixupmessages>
+            <!-- Silence a warning that claims the default package is a "split package" because both Guava and JSpecify have a root `module-info.class`. -->
+            <_fixupmessages>^Split package, multiple jars provide the same package:.*</_fixupmessages>
             <Export-Package>
               !com.google.common.base.internal,
               !com.google.common.util.concurrent.internal,
@@ -110,7 +110,7 @@
           <execution>
             <id>default-compile</id>
             <configuration>
-              <compilerArgs combine.children="append" combine.self="append">
+              <compilerArgs combine.children="append">
                 <arg>-XDignore.symbol.file</arg>
               </compilerArgs>
             </configuration>

android/pom.xml

@@ -215,7 +215,7 @@
             <target>1.8</target>
             <encoding>UTF-8</encoding>
             <parameters>true</parameters>
-            <compilerArgs combine.children="override">
+            <compilerArgs>
               <!-- https://errorprone.info/docs/installation#maven -->
               <arg>-XDcompilePolicy=simple</arg>
               <arg>--should-stop=ifError=FLOW</arg>

guava-bom/pom.xml

@@ -71,6 +71,14 @@
 
   <build>
     <plugins>
+      <plugin>
+        <artifactId>maven-clean-plugin</artifactId>
+        <version>3.5.0</version>
+      </plugin>
+      <plugin>
+        <artifactId>maven-install-plugin</artifactId>
+        <version>3.1.4</version>
+      </plugin>
       <plugin>
         <groupId>org.sonatype.central</groupId>
         <artifactId>central-publishing-maven-plugin</artifactId>

guava-testlib/pom.xml

@@ -81,7 +81,7 @@
           <execution>
             <id>default-compile</id>
             <configuration>
-              <compilerArgs combine.children="append" combine.self="append">
+              <compilerArgs combine.children="append">
                 <arg>-XDignore.symbol.file</arg>
               </compilerArgs>
             </configuration>

guava/pom.xml

@@ -79,8 +79,8 @@
         </executions>
         <configuration>
           <instructions>
-            <!-- Silence a warning that claims that META-INF/versions/9/... is the "wrong directory" for our classes. -->
-            <_fixupmessages>^Classes found in the wrong directory: .*</_fixupmessages>
+            <!-- Silence a warning that claims the default package is a "split package" because both Guava and JSpecify have a root `module-info.class`. -->
+            <_fixupmessages>^Split package, multiple jars provide the same package:.*</_fixupmessages>
             <Export-Package>
               !com.google.common.base.internal,
               !com.google.common.util.concurrent.internal,
@@ -103,7 +103,7 @@
           <execution>
             <id>default-compile</id>
             <configuration>
-              <compilerArgs combine.children="append" combine.self="append">
+              <compilerArgs combine.children="append">
                 <arg>-XDignore.symbol.file</arg>
               </compilerArgs>
             </configuration>

pom.xml

@@ -216,7 +216,7 @@
             <target>1.8</target>
             <encoding>UTF-8</encoding>
             <parameters>true</parameters>
-            <compilerArgs combine.children="override">
+            <compilerArgs>
               <!-- https://errorprone.info/docs/installation#maven -->
               <arg>-XDcompilePolicy=simple</arg>
               <arg>--should-stop=ifError=FLOW</arg>