Remove recurring flag from DoTip in rewards service in lib

[NejcZdovc]

DoTip has flag for recurring. Because we have SaveRecurringTip api now, we should remove this flag and in service call SaveRecurringTip if recurring. This should clear things

[GeetaSarvadnya]

Verification passed on

Brave	1.7.79 Chromium: 80.0.3987.149 (Official Build) dev (64-bit)
Revision	5f4eb224680e5d7dca88504586e9fd951840cac6-refs/branch-heads/3987_137@{#16}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

• Verified the test plan from Simplifies tip flow from service to shared lib brave-core#4870

Before changing the recurring tip value in panel

After changing the recurring tip value in panel

• Verified that the contribution amount for recurring tip is displayed correctly in Panel, brave://rewards settings page as well as in contribution_info and contribution_info_publisher tables

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Verified passed with

Brave	1.7.81 Chromium: 80.0.3987.149 (Official Build) dev (64-bit)
Revision	5f4eb224680e5d7dca88504586e9fd951840cac6-refs/branch-heads/3987_137@{#16}
OS	macOS Version 10.14.6 (Build 18G3020)

• Verified test plan from Simplifies tip flow from service to shared lib brave-core#4870

Before changing the recurring tip value in panel

After changing the recurring tip value in panel

• Verified that the contribution amount for recurring tip is displayed correctly in Panel, brave://rewards settings page as well as in contribution_info and contribution_info_publishers tables

Verification passed on

Brave	1.7.81 Chromium: 80.0.3987.149 (Official Build) dev (64-bit)
Revision	5f4eb224680e5d7dca88504586e9fd951840cac6-refs/branch-heads/3987_137@{#16}
OS	Ubuntu 18.04 LTS

• Verified test plan from Simplifies tip flow from service to shared lib brave-core#4870

Before changing the recurring tip value in panel

After changing the recurring tip value in panel

Verified that the contribution amount for recurring tip is displayed correctly in Panel, brave://rewards settings page as well as in contribution_info and contribution_info_publisher tables