Build multi-platform image (amd64 + arm64)

Removes the hardcoded amd64 base pin, which produced a mislabeled
arm64 manifest when built on Apple Silicon. Release target now
builds and pushes both platforms via docker buildx.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NqU8S9mRXnyQHrwvU7FFDA

Author: messeb

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=linux/amd64 ubuntu:24.04
+FROM ubuntu:24.04
 
 LABEL maintainer="messeb"
 

Makefile

@@ -1,21 +1,14 @@
 IMAGE_TAG := $(IMAGE_TAG)
 IMAGE := mobiledevops/android-sdk-image
 
-release: \
-	tag_image \
-	dockerhub_push \
-
-tag_image: build
-	docker tag $(IMAGE):latest $(IMAGE):$(IMAGE_TAG)
+release:
+	docker buildx build --platform linux/amd64,linux/arm64 \
+		-t $(IMAGE):latest -t $(IMAGE):$(IMAGE_TAG) --push .
 
 build:
 	docker build -t $(IMAGE) .
 
 run:
 	docker run -it --rm $(IMAGE) /bin/bash
 
-dockerhub_push:
-	docker push $(IMAGE):latest \
-	&& docker push "$(IMAGE):$(IMAGE_TAG)"
-
-.PHONY: release tag_image build dockerhub_push
+.PHONY: release build run