refactor(MeshService): remove `discardNodeDB` and simplify logic

app/src/main/java/com/geeksville/mesh/model/NodeDB.kt

@@ -70,14 +70,10 @@ class NodeDB @Inject constructor(
         nodeInfoDao.upsert(node)
     }
 
-    suspend fun clearNodeDB() = withContext(Dispatchers.IO) {
-        nodeInfoDao.clearNodeInfo()
-        nodeInfoDao.clearMyNodeInfo()
-    }
-
     suspend fun installNodeDB(mi: MyNodeInfo, nodes: List<NodeInfo>) = withContext(Dispatchers.IO) {
-        clearNodeDB()
+        nodeInfoDao.clearMyNodeInfo()
         nodeInfoDao.setMyNodeInfo(mi) // set MyNodeInfo first
+        nodeInfoDao.clearNodeInfo()
         nodeInfoDao.putAll(nodes)
     }
 

app/src/main/java/com/geeksville/mesh/repository/datastore/RadioConfigRepository.kt

@@ -57,7 +57,6 @@ class RadioConfigRepository @Inject constructor(
     val nodeDBbyNum: StateFlow<Map<Int, NodeInfo>> get() = nodeDB.nodeDBbyNum
 
     suspend fun upsert(node: NodeInfo) = nodeDB.upsert(node)
-    suspend fun clearNodeDB() = nodeDB.clearNodeDB()
     suspend fun installNodeDB(mi: MyNodeInfo, nodes: List<NodeInfo>) {
         nodeDB.installNodeDB(mi, nodes)
     }

app/src/main/java/com/geeksville/mesh/service/MeshService.kt

@@ -323,15 +323,6 @@ class MeshService : Service(), Logging {
     /// BEGINNING OF MODEL - FIXME, move elsewhere
     ///
 
-    /**
-     * discard entire node db - used before downloading a new db from the device
-     */
-    private fun discardNodeDB() = serviceScope.handledLaunch {
-        debug("Discarding NodeDB")
-        radioConfigRepository.clearNodeDB()
-        haveNodeDB = false
-    }
-
     val myNodeInfo: MyNodeInfo? get() = radioConfigRepository.myNodeInfo.value
 
     private val configTotal by lazy { ConfigProtos.Config.getDescriptor().fields.size }
@@ -1591,7 +1582,7 @@ class MeshService : Service(), Logging {
 
             val res = radioInterfaceService.setDeviceAddress(deviceAddr)
             if (res) {
-                discardNodeDB()
+                haveNodeDB = false
             } else {
                 serviceBroadcasts.broadcastConnection()
             }