Fix string constant declarations

When defining string constants, we typically want both the string data
and the variable referring to the string data to be immutable, which is
commonly done by declaring the string constant variables as either
`const char[]` or `const char* const`. Declaring a string constant
variable as `const char*` still allows it to point to a different
immutable string. This CL changes a few string constant declarations
from `const char*` to `const char[]`.

BUG=None
TEST=chromeos_unittests

Review-Url: https://codereview.chromium.org/2286073002
Cr-Commit-Position: refs/heads/master@{#415015}

chromeos/dbus/fake_shill_manager_client.cc

@@ -129,11 +129,11 @@ bool IsCellularTechnology(const std::string& type) {
           type == shill::kNetworkTechnologyLteAdvanced);
 }
 
-const char* kTechnologyUnavailable = "unavailable";
-const char* kNetworkActivated = "activated";
-const char* kNetworkDisabled = "disabled";
-const char* kCellularServicePath = "/service/cellular1";
-const char* kRoamingRequired = "required";
+const char kTechnologyUnavailable[] = "unavailable";
+const char kNetworkActivated[] = "activated";
+const char kNetworkDisabled[] = "disabled";
+const char kCellularServicePath[] = "/service/cellular1";
+const char kRoamingRequired[] = "required";
 
 }  // namespace
 

chromeos/disks/mock_disk_mount_manager.cc

@@ -23,18 +23,18 @@ namespace disks {
 
 namespace {
 
-const char* kTestSystemPath = "/this/system/path";
-const char* kTestSystemPathPrefix = "/this/system";
-const char* kTestDevicePath = "/this/device/path";
-const char* kTestMountPath = "/media/foofoo";
-const char* kTestFilePath = "/this/file/path";
-const char* kTestDeviceLabel = "A label";
-const char* kTestDriveLabel = "Another label";
-const char* kTestVendorId = "0123";
-const char* kTestVendorName = "A vendor";
-const char* kTestProductId = "abcd";
-const char* kTestProductName = "A product";
-const char* kTestUuid = "FFFF-FFFF";
+const char kTestSystemPath[] = "/this/system/path";
+const char kTestSystemPathPrefix[] = "/this/system";
+const char kTestDevicePath[] = "/this/device/path";
+const char kTestMountPath[] = "/media/foofoo";
+const char kTestFilePath[] = "/this/file/path";
+const char kTestDeviceLabel[] = "A label";
+const char kTestDriveLabel[] = "Another label";
+const char kTestVendorId[] = "0123";
+const char kTestVendorName[] = "A vendor";
+const char kTestProductId[] = "abcd";
+const char kTestProductName[] = "A product";
+const char kTestUuid[] = "FFFF-FFFF";
 
 }  // namespace
 

chromeos/network/network_state_handler.cc

@@ -791,7 +791,7 @@ void NetworkStateHandler::UpdateNetworkStats() {
 void NetworkStateHandler::DefaultNetworkServiceChanged(
     const std::string& service_path) {
   // Shill uses '/' for empty service path values; check explicitly for that.
-  const char* kEmptyServicePath = "/";
+  const char kEmptyServicePath[] = "/";
   std::string new_service_path =
       (service_path != kEmptyServicePath) ? service_path : "";
   if (new_service_path == default_network_path_)