fix(docker): coder-up should report some progress (#5090)

Refactor environment startup to pull images before starting.

```
❯ coder-up
Pulling image for: pr-review...
Trying to pull us-docker.pkg.dev/flutter-infra/flutter-infra/flutter_docker:stable...
Getting image source signatures
Copying blob sha256:d6cecff2cfc0d8bdbed2c1efdef4de8531c66487a8380b2b954f014daf825fc9
Copying blob sha256:7072d26cd09a3c77bb7b35b9c22b3893c89392b79baf4840e7425aacdb09e080
Copying blob sha256:cb259a83ac3dd9fea0b394df41df2b298adf0df938fef5999475af18a751c257
Copying blob sha256:86b721c394db1bb8086ba7973e5e93ea83ed9fef5b6c153886babb2c666530e1
Copying blob sha256:a3c9bf3c2c2f678b4dce5bd10dff513a847ea4d28768519d1cb59e8e4c0da5b9
Copying blob sha256:5f635f4c089e00f4b39a1b5666f94a365ebcd733fa901351a22373bdcd53f71a
Copying blob sha256:aa2962c22a5f8d7291663569925f0f78061fbc432594f6d7190e42f2d56126f5
Copying blob sha256:2815e56b3171962731fc48f3d358dfd5d4c87a68ef645c19f1fde2de83856c8f
Copying blob sha256:cbf3095671ca2d21c59e0bf0f8eabd2e9f3ac096d6d5e7124c633af529d8cb40
Copying blob sha256:15478765193d849298501e70753e4e776e8bcbf13e991ed69ee5ddcd01bfd5b5
Copying blob sha256:59647213e5b0a5ab5dbc04d5e1d6c7934b1e5b70ebcedc3af3f631a15316da63
Copying blob sha256:a1833780d6af2b6427b6dbe64d4984b13074cc86c00b07146e93e2fa995b5558
Copying config sha256:e2ce22a9680f3303f296f1fb672d91d308570df998981a722097844abad8cae3
Writing manifest to image destination
WARNING: image platform (linux/amd64) does not match the expected platform (linux/arm64)
e2ce22a9680f3303f296f1fb672d91d308570df998981a722097844abad8cae3
Starting development environment: pr-review...
WARNING: image platform (linux/amd64) does not match the expected platform (linux/arm64)
e2ce22a9680f3303f296f1fb672d91d308570df998981a722097844abad8cae3
6a534a8c0b384ae7f3897654cca354d94ec06f02542031ac6b00cbb393717a3b
6c5fbce2f44bd49a723a3bbdfd39bfc09671b243a06cfe773bec6ce55df2da33
pr-review
```

Author: jtmcdole

cloud_build/flutter_agy_docker/docker-compose.yml

@@ -8,7 +8,7 @@
 # Copy it to:  ~/.config/coder-env/docker-compose.yml
 services:
   dev:
-    image: us-docker.pkg.dev/flutter-infra/flutter-infra/flutter_docker:latest
+    image: us-docker.pkg.dev/flutter-infra/flutter-infra/flutter_docker:stable
     platform: linux/amd64
     # Dynamically reads the environment variable
     container_name: ${ENV_NAME:-coder-env}

cloud_build/flutter_agy_docker/functions.sh

@@ -26,9 +26,17 @@ coder-up() {
     return 1
   fi
 
-  echo "Starting development environment: $env_name..."
-  # 1. Spin up the environment cleanly in the background
-  ENV_NAME="$env_name" podman-compose -p "$env_name" -f "$compose_file" up -d
+
+  (
+    export ENV_NAME="$env_name"
+    # pulling the file shows progress to the user
+    echo "Pulling image for: $env_name..."
+    podman compose -p "$env_name" -f "$compose_file" pull || exit 1
+
+    # 1. Spin up the environment cleanly in the background
+    echo "Starting development environment: $env_name..."
+    podman compose -p "$env_name" -f "$compose_file" up -d
+  )
 }
 
 # Enter the container
@@ -70,5 +78,5 @@ coder-down() {
   fi
 
   echo "Stopping development environment: $env_name..."
-  ENV_NAME="$env_name" podman-compose -p "$env_name" -f "$compose_file" down
+  ENV_NAME="$env_name" podman compose -p "$env_name" -f "$compose_file" down
 }