cleanup libui’s includes

- remove unneeded includes
- include a cpp’s header first in all cpps


Test: compiled & booted
Bug: 35164655
Change-Id: I0890913fcc6614cce156aff19fccdef183145beb
diff --git a/include/ui/GraphicBufferAllocator.h b/include/ui/GraphicBufferAllocator.h
index 2ccc44b..e97122b 100644
--- a/include/ui/GraphicBufferAllocator.h
+++ b/include/ui/GraphicBufferAllocator.h
@@ -20,11 +20,14 @@
 
 #include <stdint.h>
 
+#include <memory>
+#include <string>
+
 #include <cutils/native_handle.h>
 
 #include <utils/Errors.h>
 #include <utils/KeyedVector.h>
-#include <utils/threads.h>
+#include <utils/Mutex.h>
 #include <utils/Singleton.h>
 
 #include <ui/Gralloc1.h>
@@ -36,7 +39,6 @@
 class Allocator;
 }
 
-class Gralloc1Loader;
 class GraphicBufferMapper;
 class String8;