coroutines: use lifecycleScope where appropriate

There's still a bit of GlobalScope lingering around, which might be
removable.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

ui/src/main/java/com/wireguard/android/preference/VersionPreference.kt

@@ -16,8 +16,8 @@ import com.wireguard.android.R
 import com.wireguard.android.backend.Backend
 import com.wireguard.android.backend.GoBackend
 import com.wireguard.android.backend.WgQuickBackend
+import com.wireguard.android.util.lifecycleScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.util.Locale
@@ -47,7 +47,7 @@ class VersionPreference(context: Context, attrs: AttributeSet?) : Preference(con
     }
 
     init {
-        GlobalScope.launch(Dispatchers.Main.immediate) {
+        lifecycleScope.launch(Dispatchers.Main.immediate) {
             val backend = Application.getBackend()
             versionSummary = getContext().getString(R.string.version_summary_checking, getBackendPrettyName(context, backend).toLowerCase(Locale.ENGLISH))
             notifyChanged()