Move bionic ("runtime") apex definition into bionic/.

Bug: http://b/139176024
Test: boots
Change-Id: Ifc3829e00b99c2f65ed932f0b42ab1ae59fec27c
diff --git a/apex/ld.config.txt b/apex/ld.config.txt
new file mode 100644
index 0000000..dae883d
--- /dev/null
+++ b/apex/ld.config.txt
@@ -0,0 +1,8 @@
+# Copyright (C) 2019 The Android Open Source Project
+#
+# Bionic loader config file for the Runtime APEX. This is a minimal config to
+# make the linker able to load itself as an executable (it just needs to exist).
+
+dir.runtime = /apex/com.android.runtime/bin/
+
+[runtime]