Add UsbDebuggingManager and UsbDebuggingActivity to LegacyUsbManager

The UsbDebuggingManager listens to adbd requests and displays a dialog
when the public key authentification fails, for the user to confirm if it
wants to allow USB debugging from the attached host. If the user chooses
to always allow USB debugging, the UsbDebuggingManager writes the public
key to adbd's config file so that the public key authenfication succeeds
next time.

Change-Id: I819b8a0428ba34b68dadeb9fa67c53abb9a85fbc
Revert "Two REMOVE_PROVIDER messages caused by race condition."

This reverts commit a102b8fb795dcc5d6b886034893ab1309149180f.
wifi: Fix StringIndexOutOfBoundsException for incorrectly encoded SSIDs

If the last character of a SSID is a unescaped backslash then WifiSsid
convertToBytes() will throw a StringIndexOutOfBoundsException and takes the
whole ROM down.

The issue was reported by andreip in the HTC One X XDA thread. His SSID was
set to "/ Andrew \".

04-10 21:33:54.265 E/AndroidRuntime(10479): *** FATAL EXCEPTION IN SYSTEM PROCESS: WifiStateMachine
04-10 21:33:54.265 E/AndroidRuntime(10479): java.lang.StringIndexOutOfBoundsException: length=10; index=10
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.net.wifi.WifiSsid.convertToBytes(WifiSsid.java:89)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.net.wifi.WifiSsid.createFromAsciiEncoded(WifiSsid.java:54)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.net.wifi.WifiStateMachine.setScanResults(WifiStateMachine.java:1522)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.net.wifi.WifiStateMachine.access$7100(WifiStateMachine.java:103)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.net.wifi.WifiStateMachine$SupplicantStartedState.processMessage(WifiStateMachine.java:2511)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at com.android.internal.util.StateMachine$SmHandler.processMsg(StateMachine.java:905)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at com.android.internal.util.StateMachine$SmHandler.handleMessage(StateMachine.java:760)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.os.Looper.loop(Looper.java:137)
04-10 21:33:54.265 E/AndroidRuntime(10479):     at android.os.HandlerThread.run(HandlerThread.java:60)

Change-Id: I8273decacfffea4e4cae3bb957c925833dab09e2