Add libdl_android to the Runtime APEX.

Before this it ended up in /system.

Test: build & boot
Test: adb shell find system apex -name libdl_android.so | xargs adb shell ls -l
  =>
  apex/com.android.runtime/lib/bionic/libdl_android.so
  apex/com.android.runtime/lib64/bionic/libdl_android.so
  apex/com.android.runtime@1/lib/bionic/libdl_android.so
  apex/com.android.runtime@1/lib64/bionic/libdl_android.so
  system/lib/bootstrap/libdl_android.so
  system/lib/libdl_android.so -> /apex/com.android.runtime/lib/bionic/libdl_android.so
  system/lib64/bootstrap/libdl_android.so
  system/lib64/libdl_android.so -> /apex/com.android.runtime/lib64/bionic/libdl_android.so
Bug: 135753770
Change-Id: Ibabb5714e8cc0454c77ae5d42d9650c345ff1b89
diff --git a/apex/Android.bp b/apex/Android.bp
index 276541e..4fbbec1 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -29,6 +29,7 @@
         "libc",
         "libm",
         "libdl",
+        "libdl_android",
         "libc_malloc_debug",
         "libc_malloc_hooks",
     ],
diff --git a/libdl/Android.bp b/libdl/Android.bp
index 15263e9..9daa9c4 100644
--- a/libdl/Android.bp
+++ b/libdl/Android.bp
@@ -185,6 +185,11 @@
         symbol_file: "libdl_android.map.txt",
         versions: ["10000"],
     },
+
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.runtime",
+    ],
 }
 
 ndk_library {