Fix liblp imported both as static and dynamic lib

In vts_libsnapshot_test, liblp was explicitly imported as static
library, but due to the importing of libsnapshot_defaults, it also
inherited the shared importing.
The import in libsnapshot_default, is not required, drop it.

Test: manual inspection with ldd
Bug: 148889015
Signed-off-by: Alessio Balsini <balsini@google.com>
Change-Id: I12ba0516a482dc917848b5f34cccc659a60a4803
Merged-in: I12ba0516a482dc917848b5f34cccc659a60a4803