Revert "Revert "Remove obsolete workaround for ClickableSpan a11y""

This reverts commit ee3beb64.

Instead of using BuildCompat.isAtLeastO, use Build.VERSION.SDK_INT
check the disable LinkAccessibilityHelper on versions above N MR1.

This is required because BuildCompat.isAtLeastO requires support lib
version 26, and therefore targetSdk 26. But since GMS core has a
dependency on this library, and modules not in the O sidecar cannot
target API 26 yet, setup wizard lib cannot use that method.

Test: ./gradlew connectedAndroidTest test
Bug: 37792269
Change-Id: I2be64e41cc86b4695a1ffd1ee376a774a3570750