Remove support for Valgrind in ART.

- Disable test configuration art-gtest-valgrind64
  (art-gtest-valgrind32 was already disabled).
- Remove Makefile logic regarding testing with Valgrind.
- Remove occurrences of `TEST_DISABLED_FOR_MEMORY_TOOL_VALGRIND`.
- Replace occurrences of `TEST_DISABLED_FOR_MEMORY_TOOL_ASAN` with
  `TEST_DISABLED_FOR_MEMORY_TOOL`.
- Replace the potentially dynamically evaluated
  `RUNNING_ON_MEMORY_TOOL` expression with constant
  `kRunningOnMemoryTool`.
- Simplify and fold the logic of
  `art::ArenaAllocatorMemoryToolCheckImpl` and
  `art::ArenaAllocatorMemoryToolCheck` into
  `art::ArenaAllocatorMemoryTool`.
- Adjust comments regarding memory tools.
- Remove Valgrind suppression files.
- Remove `--callgrind` option from tools/art.

Test: art/test.py
Bug: 77856586
Bug: 29282211
Change-Id: Ifdcbfccc1830104c455760457df66ede4a4cd135