change /data/bugreports to /bugreports

It's 5 characters shorter, has no runtime costs, can be stored on a
read-only partition, and avoids problems like b/27262109 and b/27204904.
It allows makes some security hardening easier.

(cherry picked from commit c4084c66)

Bug: 27262109
Bug: 27204904
Bug: 32799236
Test: verified new symlink created and old one not present
Change-Id: Ief362e13569ad9c868a7f0f9c4dbd6a328c96c6b
(cherry picked from commit 04bbd5c6)

rootdir/Android.mk

@@ -123,6 +123,7 @@ endif
 LOCAL_POST_INSTALL_CMD := mkdir -p $(addprefix $(TARGET_ROOT_OUT)/, \
     sbin dev proc sys system data oem acct config storage mnt root $(BOARD_ROOT_EXTRA_FOLDERS)); \
     ln -sf /system/etc $(TARGET_ROOT_OUT)/etc; \
+    ln -sf /data/user_de/0/com.android.shell/files/bugreports $(TARGET_ROOT_OUT)/bugreports; \
     ln -sf /sys/kernel/debug $(TARGET_ROOT_OUT)/d; \
     ln -sf /storage/self/primary $(TARGET_ROOT_OUT)/sdcard
 ifdef BOARD_USES_VENDORIMAGE

rootdir/init.rc

@@ -444,10 +444,6 @@ on post-fs-data
 
     mkdir /data/anr 0775 system system
 
-    # symlink to bugreport storage location
-    rm /data/bugreports
-    symlink /data/user_de/0/com.android.shell/files/bugreports /data/bugreports
-
     # Separate location for storing security policy files on data
     mkdir /data/security 0711 system system