Fix BasicNfcEeTest java package.

It was in com.android.nfc_extras, which caused it to get bundled with
com.android.nfc_extras.jar, which caused all kinds of confusion when
trying to push new versions of the test.

It should be in com.android.nfc_extras.tests

Also fix getContext() -> getTargetContext().

Change-Id: I1e3afa150809a3ed8c4f88531f039fe7797aca1d