Use shared libutils instead of static for keystore fuzzers

Bug: http://b/197965342

These fuzzers depend on libhidlbase.so which already depends on
libutils.so.  Moving to shared dep for them doesn't increase their
shared-library closure.  Using libutils.a instead causes build failures
with upstream lld because lld tries to fetch symbols from libutils.a to
resolve undefined symbols from libhidlbase as well.

Test: cherry-pick aosp/2036867 and `mma system/keystore`
Change-Id: I4a2d215736867032a13686c31978eaeec17fc15a
diff --git a/keystore/tests/fuzzer/Android.bp b/keystore/tests/fuzzer/Android.bp
index 589cef7..4116ae1 100644
--- a/keystore/tests/fuzzer/Android.bp
+++ b/keystore/tests/fuzzer/Android.bp
@@ -31,12 +31,12 @@
     ],
     static_libs: [
         "libkeystore-wifi-hidl",
-        "libutils",
     ],
     shared_libs: [
         "android.system.wifi.keystore@1.0",
         "libhidlbase",
         "liblog",
+        "libutils",
     ],
     fuzz_config: {
         cc: [
@@ -51,13 +51,13 @@
     static_libs: [
         "libkeystore-attestation-application-id",
         "liblog",
-        "libutils",
         "libbase",
         "libhidlbase",
     ],
     shared_libs: [
         "libbinder",
         "libcrypto",
+        "libutils",
     ],
     fuzz_config: {
         cc: [