Fix heap-buffer overflow in sdp_utils.cc

Fuzzer identifies a case where sdpu_compare_uuid_with_attr crashes with
an out of bounds comparison.  Although the bug claims this is due to a
comparison of a uuid with a smaller data field thana the discovery
attribute, my research suggests that this instead stems from a
comparison of a 128 bit UUID with a discovery attribute of some other,
invalid size.

Add checks for discovery attribute size.

Bug: 287184435
Test: atest bluetooth_test_gd_unit, net_test_stack_sdp
Tag: #security
Ignore-AOSP-First: Security
Change-Id: Id06699e51937515b2465f0b3ad72eab9e0a8e532