[Thread] add Thread aconfig_declaration to java_sdk_library

This commit also moves Thread flags to Connectivity/common to ease
maintenance.

Test: m framework-connectivity-t
Bug: 317290555
Merged-In: I50f3d3b8205a5a9ee8154a649318a2c175edbb71
Merged-In: I8a71f4ee49cc68a9512f432e454469200f2a5058
Change-Id: I8a71f4ee49cc68a9512f432e454469200f2a5058
diff --git a/framework-t/Android.bp b/framework-t/Android.bp
index e40b55c..468cee4 100644
--- a/framework-t/Android.bp
+++ b/framework-t/Android.bp
@@ -197,6 +197,7 @@
     ],
     aconfig_declarations: [
         "com.android.net.flags-aconfig",
+        "com.android.net.thread.flags-aconfig",
         "nearby_flags",
     ],
 }