ANDROID: change function signatures for some random functions.

In 5.4.200 the functions add_device_randomness() and get_random_bytes()
want from:
	void get_random_bytes(void *buf, int len);
		->
	void get_random_bytes(void *buf, size_t len);

	void add_device_randomness(const void *buf, unsigned int len);
		->
	void add_device_randomness(const void *buf, size_t len);

As these functions are part of the GKI abi to be preserved, move them
back.  As these are just lengths of the buffer, all is fine with the
size, they should never overflow.

Bug: 161946584
Fixes: b5306841 ("random: make more consistent use of integer types")
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I5430259958b9a904e6e8b950e11526332c919c0c