Remove XOM properties.

XOM is no longer supported by the build system, so remove these
properties.

Bug: 123034666
Bug: 147300048
Test: Build succeeds.
Change-Id: I77efc98241f45b1a78b1cca5560f64eef5ef22f4
diff --git a/linker/Android.bp b/linker/Android.bp
index e21ee60..d2d5f8a 100644
--- a/linker/Android.bp
+++ b/linker/Android.bp
@@ -350,7 +350,6 @@
     },
 
     compile_multilib: "both",
-    xom: false,
 
     recovery_available: true,
     apex_available: [
diff --git a/tests/libs/Android.bp b/tests/libs/Android.bp
index fdf2cca..847c353 100644
--- a/tests/libs/Android.bp
+++ b/tests/libs/Android.bp
@@ -341,10 +341,6 @@
         "libnstest_public",
         "libnstest_private",
     ],
-    // The dlext.ns_anonymous test copies the loaded segments of this shared
-    // object into a new mapping, so every segment must be readable. Turn off
-    // eXecute-Only-Memory. See http://b/123034666.
-    xom: false,
 }
 
 cc_test_library {