Remove ART dependence on property debug.allocTracker.stackDepth

Added VMDebug API to set this property. It will be called from framework
code.

Test: test-art-host
Bug: 37291459

Change-Id: I832a013fc8685bf063809e9394e0524bd9cd422e
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc
index 7a565bd..987b239 100644
--- a/runtime/gc/heap.cc
+++ b/runtime/gc/heap.cc
@@ -303,6 +303,7 @@
       blocking_gc_count_rate_histogram_("blocking gc count rate histogram", 1U,
                                         kGcCountRateMaxBucketCount),
       alloc_tracking_enabled_(false),
+      alloc_record_depth_(AllocRecordObjectMap::kDefaultAllocStackDepth),
       backtrace_lock_(nullptr),
       seen_backtrace_count_(0u),
       unique_backtrace_count_(0u),