Organize services/tests/PackageManager* for PackageManager

This patch adds 3 CTS test cases for PackageManager. They are the
following.
presubmit:
* PackageInstallerTests: Pixel 3 takes less than 5 seconds
* PackageManagerServiceUnitTests: Pixel 3 takes less than 5 seconds
* PackageManagerComponentOverrideTests: Pixel 3 takes less than 5
                                        seconds
* AppEnumerationInternalTests(moving location): Pixel 3 takes 10
                                                seconds

postsubmit:
* PackageManagerServiceHostTests: Pixel 4 5G takes 1 hour 17 minutes

When the developers change any code in
frameworks/base/service/core/java/com/android/server/pm and
frameworks/base/service/core/java/android/content/pm, it should invoke
all of the tests under cts/hostsidetests/packagemanager.

Why does this patch change AppEnumerationInternalTests from
frameworks/base/services/core/java/com/android/server/pm/TEST_MAPPING
to
frameworks/base/services/tests/PackageManagerServiceTests/TEST_MAPPING?
When developers uploads the gerrit patches to modify the content of
AppEnumerationInternalTests, presubmit process won't trigger
AppEnumerationInternalTests except for moving to
frameworks/base/services/tests/PackageManagerServiceTests/TEST_MAPPING.

Test: atest -c --dry-run -p \
    frameworks/base/services/tests/PackageManagerServiceTests:presubmit
Test: atest -c --dry-run -p \
    frameworks/base/services/tests/PackageManagerServiceTests
Test: atest -c --dry-run -p \
    frameworks/base/services/tests/PackageManager:presubmit
Test: TEST_BASE="frameworks/base/services" ;\
      atest -c --dry-run -p \
    ${TEST_BASE}/testsPackageManagerComponentOverrideTests:presubmit

Bug: 180650365
Change-Id: I62de692f7b5a33e3737effea622ed3f2460c64c3