[BUG] Some tests modify machine state #1275

Describe the bug
Some SOF tests modify machine state by setting controls to some arbitrary values and not resetting them after.

Tests I've detected on a quick look-through:

• check-keyword-detection.sh sets the volume at 40 and does not seem to reset it after.
• check-volume-levels.sh modifies a lot of amixer controls and should be looked at when handling this issue.
• volume-basic-test.sh calls the reset_sof_volume function rather than the full set_alsa_settings.
  • Note that this issue directly had its hand in the FAILs mentioned in this PR.

verify-bootsequence.sh can theoretically mess up the settings if the test crashes, but I'd like to mention it as an example for a possible new approach of a common test runner. Were we to alsactl store -f FILE the machine state before each test and then alsactl restore -f FILE after, we would be able to avoid such issues.

To Reproduce
For example, run volume-basic-test.sh and then a check-alsabat.sh test on a RT712. The latter will currently fail.

Expected behavior
Test leaves the machine in the same state as it was before the test.

Detail Info (for the aforementioned example)

1. Branch name and commit hash of the 3 repositories: sof (firmware/topology), linux (kernel driver) and sof-test (test case)
   • Kernel: 02394a2ff051
   • SOF: 9eed235129cb
   • SOF-TEST: 396efce
2. Test report ID (if you find it from test report)
   • ID: N/A
3. Test DUT Model (or a brief describtion about the device)
   • MODEL: PTLH_SDW_RT712
4. Test TPLG
   • TPLG: sof-ptl-rt712-l2-rt1320-l1
5. Test case (what test script and how you run it)
   • TESTCASE: TPLG=<topology_dir>/sof-ipc4-tplg/sof-ptl-rt712-l2-rt1320-l1.tplg MODEL=PTLH_SDW_RT712 SOF_TEST_INTERVAL=5 ~/sof-test/test-case/volume-basic-test.sh -l 50, then TPLG=<topology_dir>/sof-ipc4-tplg/sof-ptl-rt712-l2-rt1320-l1.tplg MODEL=PTLH_SDW_RT712 SOF_TEST_INTERVAL=5 ~/sof-test/test-case/check-alsabat.sh -p hw:sofsoundwire,0 -c hw:sofsoundwire,1 -C 2 -F 599