minadbd: rename adb_server_main to minadbd_main.

adb_server_main in adb refers to the adb server on the host, not adbd.
Since there doesn't seem to be a good reason to reuse the declaration
from adb's headers, give minadbd a main function of its own.

Change-Id: I748f1a6822dc14c726cb73ef3b533c57a6615608
diff --git a/minadbd/Android.mk b/minadbd/Android.mk
index 34631a9..7eef13e 100644
--- a/minadbd/Android.mk
+++ b/minadbd/Android.mk
@@ -11,8 +11,8 @@
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := \
-    adb_main.cpp \
     fuse_adb_provider.cpp \
+    minadbd.cpp \
     minadbd_services.cpp \
 
 LOCAL_CLANG := true