Decrease kLargeMalloc block size in ASAN unit tests.

[alekseyshl]

Summary

Make kLargeMalloc big enough to be handled by secondary allocator
and small enough to fit into quarantine for all configurations.
It become too big to fit into quarantine on Android after D27873.

[eugenis]

LGTM

compiler-rt/trunk/lib/asan/tests/asan_test_utils.h

 
 typedef uint8_t   U1;
 typedef uint16_t  U2;
 typedef uint32_t  U4;
 typedef uint64_t  U8;
 
 static const int kPageSize = 4096;
 
-const size_t kLargeMalloc = 1 << 24;
+// Big enough to be handled by secondary allocator and small enough to fit into
+// quarantine for all configurations.
+const size_t kLargeMalloc = 1 << 22;
 
 extern void free_aaa(void *p);
 extern void *malloc_aaa(size_t size);
 
 template<typename T>
 NOINLINE void asan_write(T *a) {
   *a = 0;
 }