Fix ODR violation

host_init_verifier statically links libprocessgroup, which has shared
dependency on libjsoncpp. Right now it also has shared dependency on
libjsoncpp, resulting in ODR violation:

 ERROR: AddressSanitizer: odr-violation (0x7fce895f3220):
 [1] size=8 'Json::kNullRef' external/jsoncpp/src/lib_json/json_value.cpp:37:22
 [2] size=8 'Json::kNullRef' external/jsoncpp/src/lib_json/json_value.cpp:37:22
 These globals were registered at these points:
 [1]:
 #0 0x56276926ef0d (/usr/local/google/buildbot/src/android/master/out/host/linux-x86/bin/host_init_verifier+0xd1f0d)
 #1 0x7fce894ac1d9 (/lib64/ld-linux-x86-64.so.2+0x101d9)

 [2]:
 #0 0x56276926ef0d (/usr/local/google/buildbot/src/android/master/out/host/linux-x86/bin/host_init_verifier+0xd1f0d)
 #1 0x7fce894ac1d9 (/lib64/ld-linux-x86-64.so.2+0x101d9)

Move host_init_verifier to libjsoncpp_headers to fix the ODR violation.

Bug: 139546461
Bug: 131328001
Test: Run ASAN host_init_verifier
Change-Id: I54a51138d61fff37f092ffaa0758817600a0af9d