fix(docker): bump Maven 3.9.15->3.9.16 in base image (dlcdn purged 3.9.15)

dlcdn.apache.org keeps only the current 3.9.x; 3.9.15 was removed (404),
breaking the base image build. Archive mirror is unreachable from the Docker
network here (see in-file note), so bump to the version dlcdn currently serves.

Author: phtcosta

rv-android/docker/base/Dockerfile

@@ -7,7 +7,7 @@ SHELL ["/bin/bash", "-c"]
 
 # Environment variables for installation paths as per your provided Dockerfile
 ENV JAVA_HOME=/opt/openjdk-25.0.2
-ENV MAVEN_HOME=/opt/apache-maven-3.9.15
+ENV MAVEN_HOME=/opt/apache-maven-3.9.16
 ENV ASPECTJ_HOME=/opt/aspectj
 ENV PATH=$ASPECTJ_HOME/bin:$JAVA_HOME/bin:$MAVEN_HOME/bin:$PATH
 
@@ -25,14 +25,14 @@ RUN wget https://download.java.net/java/GA/jdk25.0.2/b1e0dfa218384cb9959bdcb8971
     mv jdk-25.0.2 openjdk-25.0.2 && \
     rm openjdk-25.0.2_linux-x64_bin.tar.gz
 
-# Install Maven 3.9.15. Source URL is dlcdn.apache.org because archive.apache.org
+# Install Maven 3.9.16. Source URL is dlcdn.apache.org because archive.apache.org
 # is unreachable from Docker containers in this environment (host can reach it,
 # but the Docker network namespace consistently times out on the route — observed
 # during the gh55 build_all run). dlcdn.apache.org carries only the current
-# 3.9.x; bump 3.9.x as upstream evolves.
-RUN wget https://dlcdn.apache.org/maven/maven-3/3.9.15/binaries/apache-maven-3.9.15-bin.zip && \
-    unzip apache-maven-3.9.15-bin.zip && \
-    rm apache-maven-3.9.15-bin.zip
+# 3.9.x; bump 3.9.x as upstream evolves (3.9.15 was purged 2026-06, → 3.9.16).
+RUN wget https://dlcdn.apache.org/maven/maven-3/3.9.16/binaries/apache-maven-3.9.16-bin.zip && \
+    unzip apache-maven-3.9.16-bin.zip && \
+    rm apache-maven-3.9.16-bin.zip
 
 # Install AspectJ compiler — version must match aspectj.version in rvsec/pom.xml (1.9.25.1)
 # JVM tuning bakes -Xmx8192M (default is 64M, far too small for whole-APK weaving)