Revert "Make CompanionDeviceManager.getAllAssociations() public"

This reverts commit bf6e145a45726084d5a236603c81a86dc3eaf47d.

Bug: 266074351

Test: atest CtsCompanionDeviceManagerCoreTestCases:AssociationsChangedListenerTest
Test: atest CtsCompanionDeviceManagerCoreTestCases:RetrieveAssociationsTest

API-Coverage-Bug: 261281482

Change-Id: I77da1269c24bce84760e44d19aeeb9d862ed8fdf
3 files changed