Mark libs as double_loadable

libs(libasyncio libmemtrack libprocinfo libusbhost) have
vendor variants and they are also used by LLNDK(libmediandk)
which means these libs can be double-loaded.

deps:
- libmediandk -> libmedia_jni -> libmtp -> libasyncio
- libmediandk -> libmedia_jni -> libandroid_runtime -> libmemtrack
- libmediandk -> libmedia_jni -> libandroid_runtime -> libdebuggerd_client -> libprocinfo
- libmediandk -> libmedia_jni -> libmtp -> libusbhost

Bug: 121280180
Test: m -j
Change-Id: I2c2b5d67cf47b85a2aa8c08f85c7e1a84490cf4e
diff --git a/libasyncio/Android.bp b/libasyncio/Android.bp
index 4ab439d..0fd2a3a 100644
--- a/libasyncio/Android.bp
+++ b/libasyncio/Android.bp
@@ -27,6 +27,7 @@
     name: "libasyncio",
     defaults: ["libasyncio_defaults"],
     vendor_available: true,
+    double_loadable: true,
     recovery_available: true,
     host_supported: true,
     srcs: [