nexus: Implement wifi scanner and fix a lot of bugs

Signed-off-by: San Mehat <san@google.com>
diff --git a/nexus/ScanResult.h b/nexus/ScanResult.h
index 79b2b65..f70a1a9 100644
--- a/nexus/ScanResult.h
+++ b/nexus/ScanResult.h
@@ -38,6 +38,7 @@
 
     const char *getBssid() { return mBssid; }
     uint32_t getFreq() { return mFreq; }
+    int getLevel() { return mLevel; }
     const char *getFlags() { return mFlags; }
     const char *getSsid() { return mSsid; }
 };