Bump Android build tools to 28.0.3 in Dockerfile (#30832)

Bumps the Android build tools to 28.0.3 instead of 28.0.0 in the Dockerfile, since that is what flutter doctor wants.

dev/ci/docker_linux/Dockerfile

@@ -58,7 +58,7 @@ RUN unzip -q -d "${ANDROID_TOOLS_ROOT}" "${ANDROID_SDK_ARCHIVE}"
 # Suppressing output of sdkmanager to keep log size down
 # (it prints install progress WAY too often).
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "tools" > /dev/null
-RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "build-tools;28.0.0" > /dev/null
+RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "build-tools;28.0.3" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "platforms;android-28" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "platform-tools" > /dev/null
 RUN yes "y" | "${ANDROID_TOOLS_ROOT}/tools/bin/sdkmanager" "extras;android;m2repository" > /dev/null