Configuring the OpenTelemetry Android lib (for its version `0.3.0`)

OTelAndroidInitialization.java

// This is to enable the exporting of spans using OTLP over GRPC.
// The dependency "io.opentelemetry:opentelemetry-exporter-otlp" needs to be present in the
// host project in order to make this work, more info on this dependency in the OTel Java repo: https://github.com/open-telemetry/opentelemetry-java
Function<SpanExporter, SpanExporter> spanExporterCustomizer = new Function<>() {
    @Override
    public SpanExporter apply(SpanExporter spanExporter) {
        return OtlpGrpcSpanExporter.builder()
                .setEndpoint("https://my.server.endpoint")
                .build();
    }
};

// This is to make the metrics work (to get exported to your backend).
BiFunction<SdkMeterProviderBuilder, Application, SdkMeterProviderBuilder> metricsCustomizer = new BiFunction<>() {
    @Override
    public SdkMeterProviderBuilder apply(SdkMeterProviderBuilder builder, Application application) {
        return builder.registerMetricReader(PeriodicMetricReader.create(OtlpGrpcMetricExporter.builder()
                .setEndpoint("https://my.server.endpoint")
                .build()));
    }
};

// This is to make logs work.
BiFunction<SdkLoggerProviderBuilder, Application, SdkLoggerProviderBuilder> logsCustomizer = new BiFunction<>() {
    @Override
    public SdkLoggerProviderBuilder apply(SdkLoggerProviderBuilder sdkLoggerProviderBuilder, Application application) {
        return sdkLoggerProviderBuilder
                .addLogRecordProcessor(BatchLogRecordProcessor.builder(
                        OtlpGrpcLogRecordExporter.builder()
                                .setEndpoint("https://my.server.endpoint")
                                .build()
                ).build());
    }
};

// Initializing OpenTelemetry Android RUM:
OpenTelemetryRum openTelemetryRum = OpenTelemetryRum.builder(this /* Your Android application */)
        .addSpanExporterCustomizer(spanExporterCustomizer)
        .addMeterProviderCustomizer(metricsCustomizer)
        .addLoggerProviderCustomizer(logsCustomizer)
        .addInstrumentation(instrumentedApplication -> {
            // This is to automatically send activity and fragment lifecycle spans.
            new AndroidLifecycleInstrumentationBuilder()
                    .setVisibleScreenTracker(new VisibleScreenTracker())
                    .setStartupTimer(new AppStartupTimer())
                    .build().installOn(instrumentedApplication);
        })
        .build();

// Get the OpenTelemetry instance to start sending manual telemetry (more info on https://opentelemetry.io/docs/languages/java/instrumentation/)
OpenTelemetry openTelemetry = openTelemetryRum.getOpenTelemetry();