libusbhost: factor out frameworks descriptors -> byte[] code.

Sony needed to increase the limit for a UVC device with > 4KiB
descriptors, but there wasn't one clean place to do that. Tidy up, and
also go straight to *16KiB* which was the largest buffer any copy of
this code was using to date.

Test: treehugger
Change-Id: Ide41a217dcf4291a7d38836264f59e06967d9d91
diff --git a/libusbhost/Android.bp b/libusbhost/Android.bp
index 3883317..9ae73d0 100644
--- a/libusbhost/Android.bp
+++ b/libusbhost/Android.bp
@@ -30,11 +30,9 @@
     export_include_dirs: ["include"],
     target: {
         android: {
-            cflags: [
-                "-g",
-                "-DUSE_LIBLOG",
-            ],
+            header_libs: ["jni_headers"],
             shared_libs: ["liblog"],
+            srcs: ["usbhost_jni.cpp"],
         },
         darwin: {
             enabled: false,