feat(pwa) add fastlane integration for building TWA APK

twa/fastlane/Appfile

+json_key_file("")
+package_name("org.jitsi.meet")

twa/fastlane/Fastfile

+ENV["FASTLANE_SKIP_UPDATE_CHECK"] = "1"
+opt_out_usage
+
+default_platform(:android)
+
+platform :android do
+    desc "Make a new build"
+    lane :build do
+        # Cleanup
+        gradle(task: "clean")
+
+        # Build and sign the app
+        gradle(
+            task: "assemble",
+            build_type: "Release",
+            print_command: false,
+            properties: {
+                "android.injected.signing.store.file" => ENV["JITSI_KEYSTORE"],
+                "android.injected.signing.store.password" => ENV["JITSI_KEYSTORE_PASSWORD"],
+                "android.injected.signing.key.alias" => ENV["JITSI_KEY_ALIAS"],
+                "android.injected.signing.key.password" => ENV["JITSI_KEY_PASSWORD"],
+            }
+        )
+    end
+end

twa/fastlane/README.md

+fastlane documentation
+================
+# Installation
+
+Make sure you have the latest version of the Xcode command line tools installed:
+
+```
+xcode-select --install
+```
+
+Install _fastlane_ using
+```
+[sudo] gem install fastlane -NV
+```
+or alternatively using `brew install fastlane`
+
+# Available Actions
+## Android
+### android build
+```
+fastlane android build
+```
+Make a new build
+
+----
+
+This README.md is auto-generated and will be re-generated every time [fastlane](https://fastlane.tools) is run.
+More information about fastlane can be found on [fastlane.tools](https://fastlane.tools).
+The documentation of fastlane can be found on [docs.fastlane.tools](https://docs.fastlane.tools).