Setup Android app MVP with skeleton Welcome screen

[crocsandcoffee]

📑 What does this PR do?

• Sets up the initial android app with a no-op Welcome Screen
• Minor fixes to different grade scripts to build the android app
• Fixes build issues with desktop related dependencies being used in common sources. For now I moved the affected files to a desktopMain source but we will want to fix move back shared composables and utility without the offending desktop dependencies

✅ Checklist

• [x] My pull request adheres to the code style of this project
• [x] My code requires changes to the documentation
• [x] I have updated the documentation as required
• [x] All the tests have passed

🧪 How can this PR been tested?

• Checkout this branch, and run the gradle command in the README which will build and install the APK on your connected emulator or device

🧾 Tasks Remaining: (List of tasks remaining to be implemented)

• Replace the placeholder UI with a polished welcome screen
• Hook up navigation graph for Login and Sign Up Screens
• Probably need to look at updating the Mastodon Theme so we can start using that throughout all composables.

What is remaining to be implemented in this PR? Mention a list of them

🖼️ Screenshots (if applicable):

Reminder - this screen is just a dummy UI. I just wanted to get everything up and running and commit the android setup to the repo

[crocsandcoffee]

Do not move the ui/common/src/commonMain/kotlin/social/androiddev/common/composables/ files into desktopMain/ They should be reusable from all platforms

Let's chat offline. They are referencing desktop related dependencies and as such cause build issues with the android app.

I just moved them for the quick fix to unblock getting the android app working, but you'll need to rework those utils and composables to pull out the desktop related code outside of the common/shared source set.