ci: Bump Android cross-build to Ubuntu Focal

This does not change behavior, but bumping to Focal now means it doesn't
have to be done later when Bionic is no longer used and EOL.

.cirrus.yml

@@ -182,9 +182,9 @@ task:
     FILE_ENV: "./ci/test/00_setup_env_mac_host.sh"
 
 task:
-  name: 'ARM64 Android APK [bionic]'
+  name: 'ARM64 Android APK [focal]'
   << : *GLOBAL_TASK_TEMPLATE
   container:
-    image: ubuntu:bionic
+    image: ubuntu:focal
   env:
     FILE_ENV: "./ci/test/00_setup_env_android.sh"

ci/test/00_setup_env_android.sh

@@ -9,7 +9,7 @@ export LC_ALL=C.UTF-8
 export HOST=aarch64-linux-android
 export PACKAGES="clang llvm unzip openjdk-8-jdk gradle"
 export CONTAINER_NAME=ci_android
-export DOCKER_NAME_TAG="ubuntu:bionic"
+export DOCKER_NAME_TAG="ubuntu:focal"
 
 export RUN_UNIT_TESTS=false
 export RUN_FUNCTIONAL_TESTS=false