Enable static builds of libpiex

Test: m libpiex
Change-Id: I91b7fbd0babf2f2f17fc927c1f561913361b32c0
diff --git a/Android.bp b/Android.bp
index 0687b19..57045cf 100644
--- a/Android.bp
+++ b/Android.bp
@@ -51,7 +51,7 @@
     },
 }
 
-cc_library_shared {
+cc_library {
     name: "libpiex",
     host_supported: true,
     defaults: ["piex_default_cflags"],