mincrypt: merge the two RSA verifiers

The e=3 and e=65537 implementations are nearly identical, refactor
them down into one.

(cherry picked from commit 8fdbf97652b76b19b4faff522ddcf4a9da543a86)

Change-Id: I9f858204d52a0ae880170d955bf8f29fed57ee94
diff --git a/libmincrypt/Android.mk b/libmincrypt/Android.mk
index addbed8..090d0e5 100644
--- a/libmincrypt/Android.mk
+++ b/libmincrypt/Android.mk
@@ -4,15 +4,15 @@
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libmincrypt
-LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c sha256.c
+LOCAL_SRC_FILES := rsa.c sha.c sha256.c
 include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libmincrypt
-LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c sha256.c
+LOCAL_SRC_FILES := rsa.c sha.c sha256.c
 include $(BUILD_HOST_STATIC_LIBRARY)
 
 
-# TODO: drop the hyphen once these are checked in
-include $(LOCAL_PATH)/tools/Android.mk
+include $(LOCAL_PATH)/tools/Android.mk \
+        $(LOCAL_PATH)/test/Android.mk