Add system server pm to trigger CTS PackageInstaller tests

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

service/core/java/com/android/server/pm/TEST_MAPPING already imports
core/java/android/content/pm/TEST_MAPPING which imports
cts/tests/tests/packageinstaller/TEST_MAPPING.  Adding
service/core/java/android/content/pm/TEST_MAPPING to import
core/java/android/content/pm/TEST_MAPPING is just like
service/core/java/com/android/server/pm/TEST_MAPPING.

This patch also removes invoking CtsAtomicInstallTestCases with the
file patterns because invoking CtsAtomicInstallTestCases with file
patterns is redundant. It has been imported in
cts/tests/tests/packageinstaller/TEST_MAPPING. And,
cts/tests/tests/packageinstaller/TEST_MAPPING is imported in
core/java/android/content/pm/TEST_MAPPING that is imported in
service/core/java/com/android/server/pm/TEST_MAPPING.

Test: atest --collect-test-only -p \
      frameworks/base/services/core/java/com/android/server/pm
Test: atest --collect-test-only -p \
      frameworks/base/services/core/java/android/content/pm

Bug: 180650365
Change-Id: If24e4b2308891775965cb7b2659cb7e25f255436