Throw IOException on multiple connects.

Only one TagTechnology can be connected at a time.
Other calls to connect() will return IOException.

Bug: 144398423
Test: check error on multiple connects
Change-Id: I19a5f33c7f0d3e7592fe7791c1e04ddc2c9d6125
diff --git a/core/java/android/nfc/Tag.java b/core/java/android/nfc/Tag.java
index 8bb2df0..b9e6ff4 100644
--- a/core/java/android/nfc/Tag.java
+++ b/core/java/android/nfc/Tag.java
@@ -455,12 +455,12 @@
      *
      * @hide
      */
-    public synchronized void setConnectedTechnology(int technology) {
-        if (mConnectedTechnology == -1) {
-            mConnectedTechnology = technology;
-        } else {
-            throw new IllegalStateException("Close other technology first!");
+    public synchronized boolean setConnectedTechnology(int technology) {
+        if (mConnectedTechnology != -1) {
+            return false;
         }
+        mConnectedTechnology = technology;
+        return true;
     }
 
     /**
diff --git a/core/java/android/nfc/tech/BasicTagTechnology.java b/core/java/android/nfc/tech/BasicTagTechnology.java
index b6b347c..ae468fe 100644
--- a/core/java/android/nfc/tech/BasicTagTechnology.java
+++ b/core/java/android/nfc/tech/BasicTagTechnology.java
@@ -75,7 +75,10 @@
 
             if (errorCode == ErrorCodes.SUCCESS) {
                 // Store this in the tag object
-                mTag.setConnectedTechnology(mSelectedTechnology);
+                if (!mTag.setConnectedTechnology(mSelectedTechnology)) {
+                    Log.e(TAG, "Close other technology first!");
+                    throw new IOException("Only one TagTechnology can be connected at a time.");
+                }
                 mIsConnected = true;
             } else if (errorCode == ErrorCodes.ERROR_NOT_SUPPORTED) {
                 throw new UnsupportedOperationException("Connecting to " +