Circular dependency found for dimension for google-analytics-data

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#### Environment details

- OS: macOS 10.15.6
- Ruby version: 2.6.5
- Gem name and version: google-analytics-data (0.4.0)

#### Steps to reproduce

I am using the google-analytics-data gem to retrieve Google Analytics reports. When I try to convert the value of 'searchTerm' to lowercase, I encountered the following error. I referred to this document: [CaseExpression](https://developers.google.com/analytics/devguides/reporting/data/v1/rest/v1beta/Dimension#CaseExpression) Could you please let me know if this attribute is not supported?

#### Code example

```ruby
credentials_path = 'sample.json'

client = Google::Analytics::Data.analytics_data { |config| config.credentials = credentials_path }

view_id = 'properties/xxxxxxxx'

dimension_filters = []
dimension_filters << Google::Analytics::Data::V1beta::Filter.new(
field_name: 'searchTerm',
string_filter: Google::Analytics::Data::V1beta::Filter::StringFilter.new(
value: "^.+$",
match_type: Google::Analytics::Data::V1beta::Filter::StringFilter::MatchType::FULL_REGEXP
)
)
filter_expression = Google::Analytics::Data::V1beta::FilterExpression.new(
and_group: Google::Analytics::Data::V1beta::FilterExpressionList.new(
expressions: dimension_filters.map{|filter| {filter: filter}},
)
)

request = Google::Analytics::Data::V1beta::RunReportRequest.new(
property: view_id,
dimensions: [
Google::Analytics::Data::V1beta::Dimension.new(
name: 'searchTerm',
dimension_expression: Google::Analytics::Data::V1beta::DimensionExpression.new(
lower_case: Google::Analytics::Data::V1beta::DimensionExpression::CaseExpression.new(dimension_name: 'searchTerm')
)
),
Google::Analytics::Data::V1beta::Dimension.new(name: 'pagePath'),
],
date_ranges: [
Google::Analytics::Data::V1beta::DateRange.new(start_date: 'yesterday', end_date: 'yesterday')
],
dimension_filter: filter_expression
)
r = client.run_report(request)
```

#### Full backtrace

```sh
Google::Cloud::InvalidArgumentError: 3:Circular dependency found for dimension: searchTerm. debug_error_string:{"created":"@1688623183.696165000","description":"Error received from peer ipv4:127.0.0.1:7890","file":"src/core/lib/surface/call.cc","file_line":906,"grpc_message":"Circular dependency found for dimension: searchTerm","grpc_status":3}
```

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Thanks!