Enable relro / bind_now when compiling Android applications.
This marks certain regions of memory as read-only after linking,
making memory corruption security vulnerabilities are harder
to exploit.
See:
* http://www.akkadia.org/drepper/nonselsec.pdf (section 6)
* http://tk-blog.blogspot.com/2009/02/relro-not-so-well-known-memory.html
Stop using the custom linker script, which inhibits
relro / bind_now support.
Change-Id: Iaebfbbb492299004f9da92b649985b6cd67d8c97
020e4919e8