Switch on detect_leaks on 64-bit platforms by default

Switch on detect_leaks on 64-bit platforms by default

       libsanitizer/
       * asan/asan_flags.cc: Switch on leak detection for 64-bit target.
       * lsan/lsan.cc: Likewise.
       * sanitizer_common/sanitizer_flags.inc: Likewise.

Neither the OBS build nor sanitized firmware build are affected.

When Tizen application developer enables ASan for his own package only and run
it in 64-bit emulator (without any additional setup) ASan will report leaks
additionally to all other error messages.

Change-Id: Id16017e9bbe5221778330287c707bdf1846f0760
Signed-off-by: Slava Barinov <v.barinov@samsung.com>