build: use uid of user building the build containers

contrib/android/Dockerfile

@@ -2,6 +2,8 @@
 
 FROM debian:bullseye@sha256:43ef0c6c3585d5b406caa7a0f232ff5a19c1402aeb415f68bcd1cf9d10180af8
 
+ARG UID=1000
+
 ENV DEBIAN_FRONTEND=noninteractive
 
 ENV ANDROID_HOME="/opt/android"
@@ -145,7 +147,7 @@ ENV USER="user"
 ENV HOME_DIR="/home/${USER}"
 ENV WORK_DIR="${HOME_DIR}/wspace" \
     PATH="${HOME_DIR}/.local/bin:${PATH}"
-RUN useradd --create-home --shell /bin/bash ${USER}
+RUN useradd --uid $UID --create-home --shell /bin/bash ${USER}
 RUN usermod -append --groups sudo ${USER}
 RUN echo "%sudo ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
 WORKDIR ${WORK_DIR}