Move JUnit tests not from telephony settings into legacy directory.

In order to enable the junit tests as a blocking presubmit, we want
to ensure that all tests within this directory are being actively
maintained. A number of these tests were migrated to robolectric
sometime in 2017-2018, and because they are no longer maintained this CL
moves them into a separate folder, so that they will not be included in
the presubmit.

Please verify that this is the appropriate action to take for these
tests. In the future, the settings team may decide to delete this legacy
directory entirely.

Note that AutoSelectPreferenceControllerTest.setChecked_isChecked_showProgressDialog
is currently failing, but we can fix it in a separate CL.

Test: make SettingsUnitTests && adb install -r out/target/product/shamu/testcases/SettingsUnitTests/arm64/SettingsUnitTests.apk
Change-Id: Iafc15b9ac69b5ca2fec76d3c0c7e247ea0017d49