Unhardcode linker soname

Set and use DT_SONAME instead.

Test: bionic-unit-tests
Change-Id: I38a246c8a43664792424e8fef96ae2ff5f743ba6
diff --git a/linker/Android.bp b/linker/Android.bp
index f802f45..a4b4573 100644
--- a/linker/Android.bp
+++ b/linker/Android.bp
@@ -130,6 +130,7 @@
         "-shared",
         "-Wl,-Bsymbolic",
         "-Wl,--exclude-libs,ALL",
+        "-Wl,-soname,ld-android.so",
     ],
 
     cflags: [