Utils: Introduce sleep function

Use it in Android plugin

Change-Id: Id3ae707d5425e99a2e5b993e1ed98dddd73809a9
Reviewed-by: hjk <hjk121@nokiamail.com>

src/libs/utils/utils.qbs

@@ -151,6 +151,8 @@ QtcLibrary {
         "settingsselector.cpp",
         "settingsselector.h",
         "settingsutils.h",
+        "sleep.cpp",
+        "sleep.h",
         "statuslabel.cpp",
         "statuslabel.h",
         "stringutils.cpp",