Android: Use adb:// in ConnectRemote

This is apparently the right thing to do anyway and also helps to
select the right emulator or device when multiple ones are connected.

In that situation otherwise an error

  "Expected a single connected device, got instead 2 -
    try setting 'ANDROID_SERIAL'"

would occur.

Change-Id: I650a221d1a321d4dd9035411f85c7a68244c20e2
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/plugins/debugger/debuggerruncontrol.h

@@ -129,6 +129,7 @@ public:
     void setAbi(const ProjectExplorer::Abi &abi);
 
     Internal::TerminalRunner *terminalRunner() const;
+    DebuggerEngineType cppEngineType() const;
 
 private:
     bool fixupParameters();