Remove PackageManager.getResourcesForApplicationAsUser API

To switch another user to do something should create the context of the
specified user by using Context.createContextAsUser rather than call
*AsUser API directly.

Replacing PackageManager.getResourcesForApplicationAsUser with
context.createContextAsUser(...) applys in not only ShortcutService
but also the related ShortcutManager test.

Test: TEST_NAME="FrameworksServicesTests"; \
    PACKAGE_NAME="com.android.server.pm.ShortcutManagerTest"; \
    MODULE_LIST="CtsShortcutHostTestCases CtsShortcutManagerTestCases"; \
    for i in `seq 1 11`; \
    do\
      MODULE_LIST="${MODULE_LIST} ${TEST_NAME}:${PACKAGE_NAME}${i}"; \
    done; \
    atest $MODULE_LIST
Test: make -j droid cts gts vts
Test: make -j docs
Test: atest SystemUITests \
    FrameworksServicesTests:com.android.server.pm
Bug: 170928809
Change-Id: I5a4acce42b0d71e405412f84aaa73c0dfbb610e4