Fix selective build and custom ops examples

Author: larryliu0820

examples/portable/custom_ops/CMakeLists.txt

@@ -40,9 +40,8 @@ set(_common_compile_options -Wno-deprecated-declarations -fPIC)
 set(_common_include_directories ${EXECUTORCH_ROOT}/..)
 
 find_package(executorch CONFIG REQUIRED)
-find_package(
-  gflags REQUIRED PATHS ${CMAKE_CURRENT_BINARY_DIR}/../../../third-party
-)
+set(gflags_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../../third-party/gflags/gflags-build)
+find_package(gflags REQUIRED)
 
 target_include_directories(executorch INTERFACE ${_common_include_directories})
 

examples/selective_build/CMakeLists.txt

@@ -39,9 +39,8 @@ set(_common_compile_options -Wno-deprecated-declarations -fPIC)
 set(_common_include_directories ${EXECUTORCH_ROOT}/..)
 
 find_package(executorch CONFIG REQUIRED)
-find_package(
-  gflags REQUIRED PATHS ${CMAKE_CURRENT_BINARY_DIR}/../../third-party
-)
+set(gflags_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../../../third-party/gflags/gflags-build)
+find_package(gflags REQUIRED)
 
 target_include_directories(executorch_core INTERFACE ${_common_include_directories})