Update build image for sdk 31

.gitlab-ci.yml

@@ -57,7 +57,7 @@ cache: &global_cache
   before_script: 
     - git fetch --unshallow --tags
   after_script:
-    - export versionCode=`$ANDROID_HOME/build-tools/30.0.2/aapt dump badging $apk_file | grep versionCode | awk '{print $3}' | sed s/versionCode=//g | sed s/\'//g`
+    - export versionCode=`$ANDROID_HOME/build-tools/31.0.3/aapt dump badging $apk_file | grep versionCode | awk '{print $3}' | sed s/versionCode=//g | sed s/\'//g`
     - apt update && apt install gettext-base
     - cat $metadata_template | envsubst > $metadata_file
   extends: .gradle-default

docker/Dockerfile

@@ -1,7 +1,7 @@
 FROM debian:stable-slim
 
-ENV ANDROID_COMPILE_SDK=30
-ENV SDK_TOOLS_VERSION=30.0.2
+ENV ANDROID_COMPILE_SDK=31
+ENV SDK_TOOLS_VERSION=31.0.3
 ENV ANDROID_CMD_TOOLS=7583922
 ENV ANDROID_HOME=/opt/android-sdk-linux
 ENV PATH "/opt/android-sdk-linux/cmdline-tools/bin:${PATH}"