Bypass app package visibility for package name check

With this change, MediaRouter2 will validate package name against the
full list of installed packages, rather than the app's restricted
package list. This will avoid MediaRouter2 failing to validate existing
package names.

Test: atest CtsMediaBetterTogetherTestCases MediaRouter2HostSideTest
Bug: 260870618
Bug: 238178508
Change-Id: I38031e98228b3783889a5eeefd7478ec22663516