Remove duplicated libdl from shared_libs

Test: Pixel 2017 builds and boots.  Media works.
Change-Id: Ifb78ab4f7018db3cdb8f64b9dbe79d26150a573b
diff --git a/media/libstagefright/Android.bp b/media/libstagefright/Android.bp
index ac4e819..b764c98 100644
--- a/media/libstagefright/Android.bp
+++ b/media/libstagefright/Android.bp
@@ -98,7 +98,6 @@
         "libstagefright_flacdec",
         "libstagefright_foundation",
         "libstagefright_xmlparser",
-        "libdl",
         "libRScpp",
         "libhidlbase",
         "libhidlmemory",