Reduce the leak warning volume

[Dzmitry Malyshau]

I.e. if a heap is dropped, seeing the individual messages about leaked allocations is not useful:

[2020-09-24T03:30:53Z ERROR gfx_memory::heaps] Heaps not completely freed before drop. Utilization: MemoryHeapUtilization { utilization: MemoryUtilization { used: 339165
184, effective: 201221888 }, size: 6187708416 }
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(11714560) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(2928640) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(12259328) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(3067904) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(2895872) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(256) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(2048) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(16384) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(131072) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(32768) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(262144) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(65536) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(524288) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(1048576) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(2097152) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(1280) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(10240) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(81920) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(20480) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(163840) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(40960) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(327680) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(655360) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(1310720) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(47185920) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(11796480) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(512) is still used
[2020-09-24T03:30:53Z ERROR gfx_memory::allocator::general] Memory leak: SizeEntry(28160) is still used

reported by @m4b