ui: do not allow double clicking fab to show menu twice

Exception java.lang.IllegalStateException:
  at androidx.fragment.app.FragmentStore.addFragment (FragmentStore.java:92)
  at androidx.fragment.app.FragmentManager.addFragment (FragmentManager.java:1481)
  at androidx.fragment.app.BackStackRecord.executeOps (BackStackRecord.java:387)
  at androidx.fragment.app.FragmentManager.executeOps (FragmentManager.java:1965)
  at androidx.fragment.app.FragmentManager.executeOpsTogether (FragmentManager.java:1873)
  at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute (FragmentManager.java:1823)
  at androidx.fragment.app.FragmentManager.execPendingActions (FragmentManager.java:1760)
  at androidx.fragment.app.FragmentManager$5.run (FragmentManager.java:547)
  at android.os.Handler.handleCallback (Handler.java:938)
  at android.os.Handler.dispatchMessage (Handler.java:99)
  at android.os.Looper.loop (Looper.java:268)
  at android.app.ActivityThread.main (ActivityThread.java:8101)
  at java.lang.reflect.Method.invoke
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:627)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:997)

Signed-off-by: Jason A. Donenfeld <[email protected]>

Author: zx2c4

ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.kt

@@ -97,6 +97,8 @@ class TunnelListFragment : BaseFragment() {
         val bottomSheet = AddTunnelsSheet()
         binding?.apply {
             createFab.setOnClickListener {
+                if (childFragmentManager.findFragmentByTag("BOTTOM_SHEET") != null)
+                    return@setOnClickListener
                 childFragmentManager.setFragmentResultListener(AddTunnelsSheet.REQUEST_KEY_NEW_TUNNEL, viewLifecycleOwner) { _, bundle ->
                     when (bundle.getString(AddTunnelsSheet.REQUEST_METHOD)) {
                         AddTunnelsSheet.REQUEST_CREATE -> {