android: Fix search not filtering machines from input (#478)

android: Fix search not filtering text input

Fixes tailscale/tailscale#13218

* Filtering machines in the textfield works since the flow is now reachable
* Updating the health icon works since the flow is now reachable

Signed-off-by: Josh Vocal <joshvocal@gmail.com>

android/src/main/java/com/tailscale/ipn/ui/viewModel/MainViewModel.kt

@@ -23,9 +23,11 @@ import com.tailscale.ipn.ui.util.PeerCategorizer
 import com.tailscale.ipn.ui.util.PeerSet
 import com.tailscale.ipn.ui.util.TimeUtil
 import com.tailscale.ipn.ui.util.set
+import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.debounce
 import kotlinx.coroutines.launch
 import java.time.Duration
 
@@ -38,6 +40,7 @@ class MainViewModelFactory(private val vpnViewModel: VpnViewModel) : ViewModelPr
   }
 }
 
+@OptIn(FlowPreview::class)
 class MainViewModel(private val vpnViewModel: VpnViewModel) : IpnViewModel() {
 
   // The user readable state of the system
@@ -112,6 +115,14 @@ class MainViewModel(private val vpnViewModel: VpnViewModel) : IpnViewModel() {
           }
     }
 
+    viewModelScope.launch {
+      searchTerm
+        .debounce(250L)
+        .collect { term ->
+          peers.set(peerCategorizer.groupedAndFilteredPeers(term))
+        }
+    }
+
     viewModelScope.launch {
       Notifier.netmap.collect { it ->
         it?.let { netmap ->
@@ -131,16 +142,12 @@ class MainViewModel(private val vpnViewModel: VpnViewModel) : IpnViewModel() {
           }
         }
       }
-
-      viewModelScope.launch {
-        searchTerm.collect { term -> peers.set(peerCategorizer.groupedAndFilteredPeers(term)) }
     }
 
     viewModelScope.launch {
       App.get().healthNotifier?.currentIcon?.collect { icon -> healthIcon.set(icon) }
     }
   }
-  }
 
   fun showVPNPermissionLauncherIfUnauthorized() {
     val vpnIntent = VpnService.prepare(App.get())